Treatment with anti-alpha2 integrin antibodies

ABSTRACT

The invention relates to a formulation of an anti-α2 integrin antibody for administration to a patient, which is suitable for the treatment of cancer.

TECHNICAL FIELD

The present invention relates to treatment of cancer. More specifically the invention relates to methods of treating cancer by administering antibodies directed to α2β1 integrin.

BACKGROUND OF THE INVENTION

The integrin α2β1 (Very late antigen 2; VLA-2) is expressed on a variety of cell types including platelets, vascular endothelial cells, epithelial cells, activated monocytes/macrophages, fibroblasts, leukocytes, lymphocytes, activated neutrophils and mast cells. (Hemler, Annu Rev Immunol 8:365:365-400 (1999); Wu and Santoro, Dev. Dyn. 206:169-171 (1994); Edelson et. al., Blood. 103(6):2214-20 (2004); Dickeson et al, Cell Adhesion and Communication. 5: 273-281 (1998)). The most typical ligands for α2β1 include collagen and laminin, both of which are found in extracellular matrix. Typically the I-domain of the α2 integrin binds to collagen in a divalent-cation dependent manner whereas the same domain binds to laminin through both divalent-cation dependent and independent mechanisms. (Dickeson et al, Cell Adhesion and Communication. 5: 273-281 (1998)) The specificity of the α2β1 integrin varies with cell type and serves as a collagen and/or laminin receptor for particular cell types, for example α2β1 integrin is known as a collagen receptor for platelets and a laminin receptor for endothelial cells. (Dickeson et al, J Biol. Chem. 272: 7661-7668 (1997)) Echovirus-1, decorin, E-cadherin, matrix metalloproteinase I (MMP-I), endorepellin and multiple collectins and the C1q complement protein are also ligands for α2β1 integrin. (Edelson et al., Blood 107(1): 143-50 (2006)) The α2β1 integrin has been implicated in several biological and pathological processes including collagen-induced platelet aggregation, cell migration on collagen, cell-dependent reorganization of collagen fibers as well as collagen-dependent cellular responses that result in increases in cytokine expression and proliferation, (Gendron, J. Biol. Chem. 278:48633-48643 (2003); Andreasen et al., J. Immunol. 171:2804-2811 (2003); Rao et al., J. Immunol. 165(9):4935-40 (2000)), aspects of T-cell, mast cell, and neutrophil function (Chan et. al., J. Immunol. 147:398-404 (1991); Dustin and de Fougerolles, Curr Opin Immunol 13:286-290 (2001), Edelson et. al., Blood. 103(6):2214-20 (2004), Werr et al., Blood 95:1804-1809 (2000), aspects of delayed type hyersensitivity contact hypersensitivity and collagen-induced arthritis (de Fougerolles et. al., J. Clin. Invest. 105:721-720 (2000); Kriegelstein et al., J. Clin. Invest. 110(12):1773-82 (2002)), mammary gland ductal morphogenesis (Keely et. al., J. Cell Sci. 108:595-607 (1995); Zutter et al., Am. J. Pathol. 155(3):927-940 (1995)), epidermal wound healing (Pilcher et. al., J. Biol. Chem. 272:181457-54 (1997)), and processes associated with VEGF-induced angiogenesis (Senger et al., Am. J. Pathol. 160(1):195-204 (2002)).

Integrin/ligand interactions can facilitate leukocyte extravasation into inflamed tissues (Jackson et al., J. Med. Chem. 40:3359-3368 (1997); Gadek et al., Science 295(5557):1086-9 (2002), Sircar et al., Bioorg. Med. Chem. 10:2051-2066 (2002)), and play a role in downstream events following the initial extravasation of leukocytes from the circulation into tissues in response to inflammatory stimuli, including migration, recruitment and activation of pro-inflammatory cells at the site of inflammation (Eble J. A., Curr. Phar. Des. 11(7):867-880 (2005)). Some antibodies that block α2β1 integrin were reported to show impact on delayed hypersensitivity responses and efficacy in a murine model of rheumatoid arthritis and a model of inflammatory bowel disease (Kriegelstein et al., J. Clin. Invest. 110(12):1773-82 (2002); de Fougerolles et. al., J. Clin. Invest. 105:721-720 (2000) and were reported to attenuate endothelial cell proliferation and migration in vitro (Senger et al., Am. J. Pathol. 160(1):195-204 (2002), suggesting that the blocking of α2β1 integrin might prevent/inhibit abnormal or higher than normal angiogenesis, as observed in various cancers.

α2β1 integrin is the only collagen-binding integrin expressed on platelets and has been implicated to play some role in platelet adhesion to collagen and hemostasis (Gruner et al., Blood 102:4021-4027 (2003); Nieswandt and Watson, Blood 102(2):449-461 (2003); Santoro et al., Thromb. Haemost. 74:813-821 (1995); Siljander et al., Blood 15:1333-1341 (2004); Vanhoorelbeke et al., Curr. Drug Targets Cardiovasc. Haematol. Disord. 3(2):125-40 (2003)). In addition, platelet α2β1 may play a role in the regulation of the size of the platelet aggregate (Siljander et al., Blood 103(4):1333-1341 (2004)).

α2β1 integrin has also been shown as a laminin-binding integrin expressed on endothelial cells (Languino et al., J Cell Bio. 109:2455-2462 (1989)). Endothelial cells are thought to attach to laminin through an integrin-mediated mechanism, however it has been suggested that the α2 I domain may function as a ligand-specific sequence involved in mediating endothelial cell interactions (Bahou et al., Blood. 84(11):3734-3741 (1994)).

It is anticipated that a therapeutic antibody that binds α2β1 integrin, including the α2β1 integrin on platelets, could result in bleeding complications. For example, antibodies targeting other platelet receptors such as GPIb (Vanhoorelbeke et al., Curr. Drug Targets Cardiovasc. Haematol. Disord. 3(2):125-40 (2003) or GP IIb/IIIa (Schell et al., Ann. Hematot. 81:76-79 (2002), Nieswandt and Watson, Blood 102(2):449-461 (2003), Merlini et al., Circulation 109:2203-2206 (2004)) have been associated with thrombocytopenia, although the mechanisms behind this are not well understood. It has been hypothesized that binding of an antibody to a platelet receptor can alter its three dimensional structure, and expose normally unexposed epitopes which then leads to platelet elimination (Merlini et al., Circulation 109:2203-2206 (2004). Indeed, the bleeding complications associated with oral doses of GP IIa/IIIb antagonists have been described as the “dark side” of this class of compounds (Bhatt and Topol, Nat. Rev. Drug Discov. 2(1):15-28 (2003)).

The anti-human α2β1 integrin blocking antibody BHA2.1 was first described by Hangan et al., (Cancer Res. 56:3142-3149 (1996)). Other anti-α2β1 integrin antibodies are known and have been used in vitro, such as the commercially available antibodies AK7 (Mazurov et al., Thromb. Haemost. 66(4):494-9 (1991), P1E6 (Wayner et al., J. Cell Biol. 107(5):1881-91 (1988)), 10G11 (Giltay et al., Blood 73(5):1235-41 (1989) and A2-11E10 (Bergelson et al., Cell Adhes. Commun. 2(5):455-64 (1994). Hangan et al., (Cancer Res. 56:3142-3149 (1996)) used the BHA2.1 antibody in vivo to study the effects of blocking α2β1 integrin function on the extravasation of human tumor cells in the liver, and the ability of these tumor cells to develop metastatic foci under antibody treatment. The Ha1/29 antibody (Mendrick and Kelly, Lab Invest. 69(6):690-702 (1993)), specific for rat and murine α2β1 integrin, has been used in vivo to study the upregulation of α2β1 integrin on T cells following LCMV viral activation (Andreasen et al., J. Immunol. 171:2804-2811 (2003)), to study SRBC-induced delayed type hypersensitivity and FITC-induced contact type-hypersensitivity responses and collagen-induced arthritis (de Fougerolles et. al., J. Clin. Invest. 105:721-720 (2000)), to study the role of α2β1 integrin in VEGF regulated angiogenesis (Senger et al., Am. J. Pathol. 160(1):195-204 (2002); Senger et al., PNAS 94(25): 13612-7 (1997)), and to study the role of α2β1 integrin in PMN locomotion in response to platelet activating factor (PAF) (Werr et al., Blood 95:1804-1809 (2000)).

The use of murine monoclonal antibodies, such as those described above, as human therapeutic agents in non-immunocompromized patients has been limited by the robust immune responses directed against administered murine antibodies, particularly in repeated administration. This response cannot only curtail the effective half-life of the murine antibody in circulation but also can lead to profound injection site and/or anaphylactic responses (Shawler et al., J. Immunol. 135(2):1530 (1985)). In addition, the rodent effector functions associated with the constant regions (Fc) are much less effective than their human counterparts when administered to humans, resulting in a loss of potentially desirable complement activation and antibody-dependent, cell-mediated cytotoxicity (ADCC) activity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: Effect of GBR500 on AsPC-1 human pancreatic cancer xenograft growth in immunodeficient female BALB/c nude (nu/nu) athymic mice.

FIG. 2: Effect of GBR500 on HT29 human colon carcinoma xenograft in nu/nu athymic mice.

FIG. 3: Western Blot analysis of CD49b and GAPDH expression in human cell lines.

FIG. 4: Confocal microscopy images of stained cell line HT1080.

FIG. 5: Confocal microscopy images of stained cell line BxPC-3.

FIG. 6: Confocal microscopy images of stained cell line MIA PaCa2.

FIG. 7: Confocal microscopy images of stained cell line HT-29.

FIG. 8: Confocal microscopy images of stained cell line SW480.

FIG. 9: Effect of GBR500 against the A549 non small cell lung cancer xenograft in nu/nu athymic mice.

FIGS. 10A and 10 B: Concentration curves of GBR500 100 mg dose group for male and female monkeys.

SUMMARY OF THE INVENTION

The present invention concerns methods of using humanized anti-alpha 2 (α2) integrin antibodies for treating cancers. In particular, the invention provides an effective approach for treating cancers selected from the group consisting of squamous cell cancer, lung cancer including small-cell lung cancer, non-small cell lung cancer, adenocarcinoma of the lung, and squamous carcinoma of the lung, cancer of the peritoneum, hepatocellular cancer, gastric or stomach cancer including gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, colorectal cancer, endometrial or uterine carcinoma, salivary gland carcinoma, kidney or renal cancer, liver cancer, prostate cancer, vulval cancer, thyroid cancer, hepatic carcinoma and various types of head and neck cancer, as well as B-cell lymphoma including low grade/follicular non-Hodgkin's lymphoma (NHL); small lymphocytic (SL) NHL; intermediate grade/follicular NHL; intermediate grade diffuse NHL; high grade immunoblastic NHL; high grade lymphoblastic NHL; high grade small non-cleaved cell NHL; bulky disease NHL; mantle cell lymphoma; AIDS-related lymphoma; and Waldenstrom's Macroglobulinemia; chronic lymphocytic leukemia (CLL); acute lymphoblastic leukemia (ALL); Hairy cell leukemia; chronic myeloblastic leukemia; and post-transplant lymphoproliferative disorder (PTLD), as well as abnormal vascular proliferation associated with phakomatoses, edema such as that associated with brain tumors, Meigs' syndrome, melanoma, mesothelioma, multiple myeloma, fibrosarcoma, osteosarcoma, and epidermoid carcinoma. This invention is based on the unexpected results that anti-alpha 2 (α2) integrin antibodies which bind specifically α2β1 integrin inhibit tumor growth to a degree comparable to anti-VEGF antibodies. VEGF factors activate or upregulate expression of integrins such as α1β1, α2β1, α4β1, α5β1 and ανβ3 on blood vessels and α4β1, α9β1, α2β1 and β1β1 on lymphatic vessels (Avraamides et al., Nat Rev Cancer. 2008 August; 8(8):604-17). It is therefore surprising that antagonism of only α2β1 leads to a similar outcome as treatment with a VEGF antibody.

Accordingly in one aspect, the invention provides a method of treating cancer selected from the group consisting of squamous cell cancer, lung cancer including small-cell lung cancer, non-small cell lung cancer, adenocarcinoma of the lung, and squamous carcinoma of the lung, cancer of the peritoneum, hepatocellular cancer, gastric or stomach cancer including gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, colorectal cancer, endometrial or uterine carcinoma, salivary gland carcinoma, kidney or renal cancer, liver cancer, prostate cancer, vulval cancer, thyroid cancer, hepatic carcinoma and various types of head and neck cancer, as well as B-cell lymphoma including low grade/follicular non-Hodgkin's lymphoma (NHL); small lymphocytic (SL) NHL; intermediate grade/follicular NHL; intermediate grade diffuse NHL; high grade immunoblastic NHL; high grade lymphoblastic NHL; high grade small non-cleaved cell NHL; bulky disease NHL; mantle cell lymphoma; AIDS-related lymphoma; and Waldenstrom's Macroglobulinemia; chronic lymphocytic leukemia (CLL); acute lymphoblastic leukemia (ALL); Hairy cell leukemia; chronic myeloblastic leukemia; and post-transplant lymphoproliferative disorder (PTLD), as well as abnormal vascular proliferation associated with phakomatoses, edema such as that associated with brain tumors, Meigs' syndrome, melanoma, mesothelioma, multiple myeloma, fibrosarcoma, osteosarcoma, and epidermoid carcinoma, comprising administering to a subject a therapeutically effective amount of a humanized anti-α2 integrin antibody comprising a heavy chain variable region comprising the amino acid sequence of (a) HCDR2 (VIWARGFTNYNSALMS, SEQ ID NO:2), (b) HCDR1 (GFSLTNYGIH, SEQ ID NO:1), HCDR2 (VIWARGFTNYNSALMS, SEQ ID NO:2) and HCDR3 (ANDGVYYAMDY, SEQ ID NO:3), or (c) SEQ ID NO:40 and/or a light chain variable region comprising the amino acid sequence of (a) an LCDR1 selected from SANSSVNYIH (SEQ ID NO:4) or SAQSSVNYIH (SEQ ID NO:112), (b) LCDR2 (DTSKLAS; SEQ ID NO:5) and (c) LCDR3 (QQWTTNPLT, SEQ ID NO:6).

In another aspect the invention provides a method of treating cancer selected from the group consisting of squamous cell cancer, lung cancer including small-cell lung cancer, non-small cell lung cancer, adenocarcinoma of the lung, and squamous carcinoma of the lung, cancer of the peritoneum, hepatocellular cancer, gastric or stomach cancer including gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, colorectal cancer, endometrial or uterine carcinoma, salivary gland carcinoma, kidney or renal cancer, liver cancer, prostate cancer, vulval cancer, thyroid cancer, hepatic carcinoma and various types of head and neck cancer, as well as B-cell lymphoma including low grade/follicular non-Hodgkin's lymphoma (NHL); small lymphocytic (SL) NHL; intermediate grade/follicular NHL; intermediate grade diffuse NHL; high grade immunoblastic NHL; high grade lymphoblastic NHL; high grade small non-cleaved cell NHL; bulky disease NHL; mantle cell lymphoma; AIDS-related lymphoma; and Waldenstrom's Macroglobulinemia; chronic lymphocytic leukemia (CLL); acute lymphoblastic leukemia (ALL); Hairy cell leukemia; chronic myeloblastic leukemia; and post-transplant lymphoproliferative disorder (PTLD), as well as abnormal vascular proliferation associated with phakomatoses, edema such as that associated with brain tumors, Meigs' syndrome, melanoma, mesothelioma, multiple myeloma, fibrosarcoma, osteosarcoma, and epidermoid carcinoma, comprising administering to a subject a composition comprising a therapeutically effective amount of a humanized anti-α2 integrin antibody comprising a heavy chain variable region comprising the amino acid sequence of (a) HCDR2 (VIWARGFTNYNSALMS, SEQ ID NO:2), (b) HCDR1 (GFSLTNYGIH, SEQ ID NO:1), HCDR2 (VIWARGFTNYNSALMS, SEQ ID NO:2) and HCDR3 (ANDGVYYAMDY, SEQ ID NO:3), or (c) SEQ ID NO:40 and/or a light chain variable region comprising the amino acid sequence of (a) an LCDR1 selected from SANSSVNYIH (SEQ ID NO:4) or SAQSSVNYIH (SEQ ID NO:112), (b) LCDR2 (DTSKLAS; SEQ ID NO:5) and (c) LCDR3 (QQWTTNPLT, SEQ ID NO:6) and a pharmaceutically acceptable carrier. Compositions for therapeutic uses may be sterile and may be lyophilized.

In another aspect the invention provides a method of treating cancer selected from the group consisting of squamous cell cancer, lung cancer including small-cell lung cancer, non-small cell lung cancer, adenocarcinoma of the lung, and squamous carcinoma of the lung, cancer of the peritoneum, hepatocellular cancer, gastric or stomach cancer including gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, colorectal cancer, endometrial or uterine carcinoma, salivary gland carcinoma, kidney or renal cancer, liver cancer, prostate cancer, vulval cancer, thyroid cancer, hepatic carcinoma and various types of head and neck cancer, as well as B-cell lymphoma including low grade/follicular non-Hodgkin's lymphoma (NHL); small lymphocytic (SL) NHL; intermediate grade/follicular NHL; intermediate grade diffuse NHL; high grade immunoblastic NHL; high grade lymphoblastic NHL; high grade small non-cleaved cell NHL; bulky disease NHL; mantle cell lymphoma; AIDS-related lymphoma; and Waldenstrom's Macroglobulinemia; chronic lymphocytic leukemia (CLL); acute lymphoblastic leukemia (ALL); Hairy cell leukemia; chronic myeloblastic leukemia; and post-transplant lymphoproliferative disorder (PTLD), as well as abnormal vascular proliferation associated with phakomatoses, edema such as that associated with brain tumors, Meigs' syndrome, melanoma, mesothelioma, multiple myeloma, fibrosarcoma, osteosarcoma, and epidermoid carcinoma, comprising administering to a subject a composition comprising a therapeutically effective amount of a humanized anti-α2 integrin antibody comprising a heavy chain variable region comprising the amino acid sequence of (a) HCDR2 (VIWARGFTNYNSALMS, SEQ ID NO:2), (b) HCDR1 (GFSLTNYGIH, SEQ ID NO:1), HCDR2 (VIWARGFTNYNSALMS, SEQ ID NO:2) and HCDR3 (ANDGVYYAMDY, SEQ ID NO:3), or (c) SEQ ID NO:40 and/or a light chain variable region comprising the amino acid sequence of (a) an LCDR1 selected from SANSSVNYIH (SEQ ID NO:4) or SAQSSVNYIH (SEQ ID NO:112), (b) LCDR2 (DTSKLAS; SEQ ID NO:5) and (c) LCDR3 (QQWTTNPLT, SEQ ID NO:6) and a pharmaceutically acceptable carrier, whereas the dosage regime is once every two weeks.

In yet a further aspect, the invention provides a humanized anti-α2 integrin antibody comprising a heavy chain variable region comprising the amino acid sequence of (a) HCDR2 (VIWARGFTNYNSALMS, SEQ ID NO:2), (b) HCDR1 (GFSLTNYGIH, SEQ ID NO:1), HCDR2 (VIWARGFTNYNSALMS, SEQ ID NO:2) and HCDR3 (ANDGVYYAMDY, SEQ ID NO:3), or (c) SEQ ID NO:40 and/or a light chain variable region comprising the amino acid sequence of (a) an LCDR1 selected from SANSSVNYIH (SEQ ID NO:4) or SAQSSVNYIH (SEQ ID NO:112), (b) LCDR2 (DTSKLAS; SEQ ID NO:5) and (c) LCDR3 (QQWTTNPLT, SEQ ID NO:6) or a composition comprising said humanized anti-α2 integrin antibody and a pharmaceutically acceptable carrier for use in a method for the treatment of cancer selected from the group consisting of squamous cell cancer, lung cancer including small-cell lung cancer, non-small cell lung cancer, adenocarcinoma of the lung, and squamous carcinoma of the lung, cancer of the peritoneum, hepatocellular cancer, gastric or stomach cancer including gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, colorectal cancer, endometrial or uterine carcinoma, salivary gland carcinoma, kidney or renal cancer, liver cancer, prostate cancer, vulval cancer, thyroid cancer, hepatic carcinoma and various types of head and neck cancer, as well as B-cell lymphoma including low grade/follicular non-Hodgkin's lymphoma (NHL); small lymphocytic (SL) NHL; intermediate grade/follicular NHL; intermediate grade diffuse NHL; high grade immunoblastic NHL; high grade lymphoblastic NHL; high grade small non-cleaved cell NHL; bulky disease NHL; mantle cell lymphoma; AIDS-related lymphoma; and Waldenstrom's Macroglobulinemia; chronic lymphocytic leukemia (CLL); acute lymphoblastic leukemia (ALL); Hairy cell leukemia; chronic myeloblastic leukemia; and post-transplant lymphoproliferative disorder (PTLD), as well as abnormal vascular proliferation associated with phakomatoses, edema such as that associated with brain tumors, Meigs' syndrome, melanoma, mesothelioma, multiple myeloma fibrosarcoma, osteosarcoma, and epidermoid carcinoma.

In a further aspect the invention provides a kit for treating cancer selected from the group consisting of squamous cell cancer, lung cancer including small-cell lung cancer, non-small cell lung cancer, adenocarcinoma of the lung, and squamous carcinoma of the lung, cancer of the peritoneum, hepatocellular cancer, gastric or stomach cancer including gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, colorectal cancer, endometrial or uterine carcinoma, salivary gland carcinoma, kidney or renal cancer, liver cancer, prostate cancer, vulval cancer, thyroid cancer, hepatic carcinoma and various types of head and neck cancer, as well as B-cell lymphoma including low grade/follicular non-Hodgkin's lymphoma (NHL); small lymphocytic (SL) NHL; intermediate grade/follicular NHL; intermediate grade diffuse NHL; high grade immunoblastic NHL; high grade lymphoblastic NHL; high grade small non-cleaved cell NHL; bulky disease NHL; mantle cell lymphoma; AIDS-related lymphoma; and Waldenstrom's Macroglobulinemia; chronic lymphocytic leukemia (CLL); acute lymphoblastic leukemia (ALL); Hairy cell leukemia; chronic myeloblastic leukemia; and post-transplant lymphoproliferative disorder (PTLD), as well as abnormal vascular proliferation associated with phakomatoses, edema such as that associated with brain tumors, Meigs' syndrome, melanoma, mesothelioma, multiple myeloma, fibrosarcoma, osteosarcoma, and epidermoid carcinoma in a human patient comprising a package comprising a humanized anti-α2 integrin antibody composition comprising a humanized anti-α2 integrin antibody comprising a heavy chain variable region comprising the amino acid sequence of (a) HCDR2 (VIWARGFTNYNSALMS, SEQ ID NO:2), (b) HCDR1 (GFSLTNYGIH, SEQ ID NO:1), HCDR2 (VIWARGFTNYNSALMS, SEQ ID NO:2) and HCDR3 (ANDGVYYAMDY, SEQ ID NO:3), or (c) SEQ ID NO:40 and/or a light chain variable region comprising the amino acid sequence of (a) an LCDR1 selected from SANSSVNYIH (SEQ ID NO:4) or SAQSSVNYIH (SEQ ID NO:112), (b) LCDR2 (DTSKLAS; SEQ ID NO:5) and (c) LCDR3 (QQWTTNPLT, SEQ ID NO:6) and instructions for using said humanized anti-α2 integrin antibody for said treatment.

In a further aspect the invention provides an article of manufacture comprising a humanized anti-α2 integrin antibody comprising a heavy chain variable region comprising the amino acid sequence of (a) HCDR2 (VIWARGFTNYNSALMS, SEQ ID NO:2), (b) HCDR1 (GFSLTNYGIH, SEQ ID NO:1), HCDR2 (VIWARGFTNYNSALMS, SEQ ID NO:2) and HCDR3 (ANDGVYYAMDY, SEQ ID NO:3), or (c) SEQ ID NO:40 and/or a light chain variable region comprising the amino acid sequence of (a) an LCDR1 selected from SANSSVNYIH (SEQ ID NO:4) or SAQSSVNYIH (SEQ ID NO:112), (b) LCDR2 (DTSKLAS; SEQ ID NO:5) and (c) LCDR3 (QQWTTNPLT, SEQ ID NO:6) a container and a label indicating the use of said humanized anti-α2 integrin antibody for treating cancer selected from the group consisting of squamous cell cancer, lung cancer including small-cell lung cancer, non-small cell lung cancer, adenocarcinoma of the lung, and squamous carcinoma of the lung, cancer of the peritoneum, hepatocellular cancer, gastric or stomach cancer including gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, colorectal cancer, endometrial or uterine carcinoma, salivary gland carcinoma, kidney or renal cancer, liver cancer, prostate cancer, vulval cancer, thyroid cancer, hepatic carcinoma and various types of head and neck cancer, as well as B-cell lymphoma including low grade/follicular non-Hodgkin's lymphoma (NHL); small lymphocytic (SL) NHL; intermediate grade/follicular NHL; intermediate grade diffuse NHL; high grade immunoblastic NHL; high grade lymphoblastic NHL; high grade small non-cleaved cell NHL; bulky disease NHL; mantle cell lymphoma; AIDS-related lymphoma; and Waldenstrom's Macroglobulinemia; chronic lymphocytic leukemia (CLL); acute lymphoblastic leukemia (ALL); Hairy cell leukemia; chronic myeloblastic leukemia; and post-transplant lymphoproliferative disorder (PTLD), as well as abnormal vascular proliferation associated with phakomatoses, edema such as that associated with brain tumors, Meigs' syndrome, melanoma, mesothelioma, multiple myeloma, fibrosarcoma, osteosarcoma, and epidermoid carcinoma.

In certain embodiments, the anti-α2 integrin antibody includes one or more human constant regions (e.g., C_(L) and/or C_(H)) and a light chain variable region comprising the amino acid sequence of SEQ ID NO:19 and/or a heavy chain variable region comprising the amino acid sequence of SEQ ID NO:21 or amino acid sequence variants thereof.

Various forms of the antibody are contemplated herein. For example, the anti-α2 integrin antibody may be a full length antibody (e.g., comprising human immunoglobulin constant regions) or an antibody fragment (e.g. Fab or F(ab′)₂ or Fab′ or Fv or scFv fragments). Furthermore, the antibody may be labeled with a detectable label, immobilized on a solid phase and/or conjugated with a heterologous compound (such as a cytotoxic agent).

In an embodiment, the above-mentioned heavy chain variable region comprises the amino acid sequence of SEQ ID NO:185.

In a further embodiment, the above-mentioned heavy chain variable region comprises the amino acid sequence of SEQ ID NO:185 in which position 30 is Thr and/or position 31 is Asn.

In a further embodiment, the above-mentioned heavy chain variable region comprises the amino acid sequence of SEQ ID NO:185 in which (a) position 71 is Lys, (b) position 73 is Asn, (c) position 78 is Val, or (d) any combination of (a)-(c).

In a further embodiment, the above-mentioned heavy chain variable region comprises an amino acid sequence selected from SEQ ID NOs:70-79 and SEQ ID NOs:109-111.

In a further embodiment, the above-mentioned heavy chain variable region comprises an amino acid sequence selected from SEQ ID NOs:70-75, SEQ ID NOs:77-79 and SEQ ID NOs:109-111.

In an embodiment, the above-mentioned heavy chain variable region further comprises a FW4 region comprising the amino acid sequence WGQGTLVTVSS (SEQ ID NO:13).

In an embodiment, the above-mentioned heavy chain variable region comprises the amino acid sequence of HCDR1 (SEQ ID NO:1), HCDR2 (SEQ ID NO:2) and HCDR3 (SEQ ID NO:3).

In a further embodiment, the above-mentioned humanized anti-α2 integrin antibody comprises a heavy chain comprising SEQ ID NO:187.

In an embodiment, the above-mentioned light chain variable region comprises the amino acid sequence of SEQ ID NO:186.

In an embodiment, the above-mentioned light chain variable region comprises the amino acid sequence of SEQ ID NO:186 in which the asparagine (N) at amino acid position 26 is replaced by glutamine (Q).

In an embodiment, the above-mentioned light chain variable region comprises the amino acid sequence of SEQ ID NO:186 in which (a) position 2 is Phe, (b) position 45 is Lys, (c) position 48 is Tyr, or (d) any combination of (a)-(c).

In an embodiment, the above-mentioned light chain variable region comprises an amino acid sequence selected from SEQ ID NO:41, SEQ ID NOs:80-92 and SEQ ID NO:108.

In an embodiment, the above-mentioned light chain variable region comprises an amino acid sequence selected from SEQ ID NOs:90-92.

In an embodiment, the above-mentioned light chain variable region further comprises a FW4 region comprising the amino acids sequence FGQGTKVEIK (SEQ ID NO:38).

In an embodiment, the above-mentioned light chain variable region comprises the amino acid sequence of LCDR1 (SEQ ID NO:4), LCDR2 (SEQ ID NO:5) and LCDR3 (SEQ ID NO:6).

In an embodiment, the above-mentioned light chain variable region comprises the amino acid sequence of LCDR1 (SEQ ID NO:112), LCDR2 (SEQ ID NO:5) and LCDR3 (SEQ ID NO:6).

In a further embodiment, the above-mentioned humanized anti-α2 integrin antibody comprises a light chain comprising SEQ ID NO:188.

In a further embodiment the above-mentioned humanized anti-α2 integrin antibody comprises:

(i) a heavy chain variable region comprising the amino acid sequence of (a) HCDR2 (VIWARGFTNYNSALMS, SEQ ID NO:2), (b) HCDR1 (GFSLTNYGIH, SEQ ID NO:1), HCDR2 (VIWARGFTNYNSALMS, SEQ ID NO:2) and HCDR3 (ANDGVYYAMDY, SEQ ID NO:3), or (c) SEQ ID NO:40; and (ii) a light chain variable region comprising the amino acid sequence of (a) an LCDR1 selected from SANSSVNYIH (SEQ ID NO:4) or SAQSSWNYIH (SEQ ID NO:112), (b) LCDR2 (DTSKLAS; SEQ ID NO:5) and (c) LCDR3 (QQWTTNPLT, SEQ ID NO:6).

In a further embodiment the above-mentioned humanized anti-α2 integrin antibody comprises:

(i) a heavy chain variable region comprising the amino acid sequence of (a) HCDR1 (GFSLTNYGIH, SEQ ID NO:1), HCDR2 (VIWARGFTNYNSALMS, SEQ ID NO:2) and HCDR3 (ANDGVYYAMDY, SEQ ID NO:3), or (b) SEQ ID NO:40; and (ii) a light chain variable region comprising the amino acid sequence of (a) an LCDR1 selected from SANSSVNYIH (SEQ ID NO:4) or SAQSSVNYIH (SEQ ID NO:112), (b) LCDR2 (DTSKLAS; SEQ ID NO:5) and (c) LCDR3 (QQWTTNPLT, SEQ ID NO:6).

In a further embodiment the above-mentioned humanized anti-α2 integrin antibody comprises:

(i) a heavy chain variable region comprising the amino acid sequence of HCDR1 (GFSLTNYGIH, SEQ ID NO:1), HCDR2 (VIWARGFTNYNSALMS, SEQ ID NO:2) and HCDR3 (ANDGVYYAMDY, SEQ ID NO:3); and (ii) a light chain variable region comprising the amino acid sequence of LCDR1 (SAQSSVNYIH, SEQ ID NO:112), LCDR2 (DTSKLAS; SEQ ID NO:5) and LCDR3 (QQWTTNPLT, SEQ ID NO:6).

Also provided is the above-mentioned method comprising the humanized anti-α2 integrin antibody, wherein (a) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO:185, (b) the light chain variable region comprises the amino acid sequence of SEQ ID NO:186, or (c) both (a) and (b).

Also provided is the above-mentioned method comprising the humanized anti-α2 integrin antibody, wherein (a) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO:185 in which position 30 is Thr and/or position 31 is Asn; (b) the light chain variable region comprises the amino acid sequence of SEQ ID NO:186 in which the asparagine (N) at amino acid position 26 is replaced by glutamine (Q); or (c) both (a) and (b).

Also provided is the above-mentioned method comprising the humanized anti-α2 integrin antibody, wherein (i) the heavy chain variable region comprises the amino acid sequence of SEQ ID NO:185 in which (a) position 71 is Lys, (b) position 73 is Asn, (c) position 78 is Val, or (d) any combination of (a)-(c); (ii) the light chain variable region comprises the amino acid sequence of SEQ ID NO:186 in which (a) position 2 is Phe, (b) position 45 is Lys, (c) position 48 is Tyr, or (d) any combination of (a)-(c); or (iii) both (i) and (ii).

Also provided is the above-mentioned method comprising the humanized anti-α2 integrin antibody, wherein (a) the heavy chain variable region comprises an amino acid sequence selected from SEQ ID NOs:70-79 and SEQ ID NOs:109-111; (b) the light chain variable region comprises an amino acid sequence selected from SEQ ID NO:41, SEQ ID NOs:80-92 and SEQ ID NO:108; or (c) both (a) and (b).

Also provided is the above-mentioned method comprising the humanized anti-α2 integrin antibody, wherein (a) the heavy chain variable region comprises an amino acid sequence selected from SEQ ID NOs:70-75, SEQ ID NOs:77-79 and SEQ ID NOs:109-111; (b) the light chain variable region comprises an amino acid sequence selected from SEQ ID NOs:90-92; or (c) both (a) and (b).

Also provided is the above-mentioned method comprising the humanized anti-α2 integrin antibody, wherein the humanized anti-α2 integrin antibody comprises a heavy chain comprising SEQ ID NO:187 and a light chain comprising SEQ ID NO:188.

Also provided is the above-mentioned method comprising the humanized anti-α2 integrin antibody, wherein the humanized anti-α2 integrin antibody comprises a heavy chain comprising SEQ ID NO:174 or SEQ ID NO:176 and a light chain comprising SEQ ID NO:178.

In an embodiment, the above-mentioned anti-α2 integrin antibody recognizes the I domain of human α2 integrin.

In an embodiment, the above-mentioned anti-α2 integrin antibody binds α2β1 integrin.

In an embodiment, the above-mentioned anti-α2 integrin antibody binds an epitope of α2 integrin, the epitope comprising:

(a) a Lys residue corresponding to position 192 of the α2 integrin amino acid sequence set forth in SEQ ID NO:8 or position 40 of the α2 integrin I domain amino acid sequence set forth in SEQ ID NO:11; (b) an Asn residue corresponding to position 225 of the α2 integrin amino acid sequence set forth in SEQ ID NO:8 or position 73 of the α2 integrin I domain amino acid sequence set forth in SEQ ID NO:11; (c) a Gln residue corresponding to position 241 of the α2 integrin amino acid sequence set forth in SEQ ID NO:8 or position 89 of the α2 integrin I domain amino acid sequence set forth in SEQ ID NO:11; (d) a Tyr residue corresponding to position 245 of the α2 integrin amino acid sequence set forth in SEQ ID NO:8 or position 93 of the α2 integrin I domain amino acid sequence set forth in SEQ ID NO:11; (e) an Arg residue corresponding to position 317 of the α2 integrin amino acid sequence set forth in SEQ ID NO:8 or position 165 of the α2 integrin I domain amino acid sequence set forth in SEQ ID NO:11; (f) an Asn residue corresponding to position 318 of the α2 integrin amino acid sequence set forth in SEQ ID NO:8 or position 166 of the α2 integrin I domain amino acid sequence set forth in SEQ ID NO:11; or (g) any combination of (a) to (f).

In an embodiment, the above-mentioned humanized anti-α2 integrin antibody is a full length antibody.

In an embodiment, the above-mentioned humanized anti-α2 integrin antibody is an antigen binding fragment.

In an embodiment, the above-mentioned humanized anti-α2 integrin antibody inhibits binding of α2 or α2β1 integrin to an α2β1 integrin ligand.

In an embodiment, the above-mentioned α2β1 integrin ligand is selected from collagen, laminin, Echovirus-1, decorin, E-cadherin, matrix metalloproteinase I (MMP-I), endorepellin, collectin and C1q complement protein.

In embodiments, the above-mentioned method is not associated with (a) platelet activation, (b) platelet aggregation, (c) a decrease in circulating platelet count, (d) bleeding complications, or (e) any combination of (a) to (d).

In an embodiment, the above-mentioned anti-α2 integrin antibody competively inhibits the binding of an antibody comprising the UL region of SEQ ID NO:19 and the VH region of SEQ ID NO:21 to human α2β1 integrin or the I domain thereof.

Preferred antibodies bind to the I-domain of human α2β1 integrin. In particular, the preferred antibodies are able to block α2-dependent adhesion of cells to the extracellular matrix (ECM), particularly to at least one or both of collagen and laminin. Humanized antibodies are provided, including antibodies based on an antibody referred to herein as TMC-2206. Anti-α2 integrin antibodies are provided that are highly specific for human α2β1 integrin, and whose administration is not associated with undesired effects such as bleeding complications or complications due to cellular activation. The binding specificity (e.g., epitope specificity) of these antibodies is associated with their unexpected non-hemorrhagic profile.

The humanized anti-α2β1 integrin antibody used in the present invention may have a heavy chain variable region comprising the amino acid sequence of HCDR1 (GFSLTNYGIH; SEQ ID NO:1) and/or HCDR2 (VIWARGFTNYNSALMS; SEQ ID NO:2) and/or HCDR3 (ANDGVYYAMDY; SEQ ID NO:3). The humanized anti-α2β1 integrin antibody may have a light chain variable region comprising the amino acid sequence of LCDR1 (SANSSVNYIH; SEQ ID NO:4 or SAQSSVNYIH; SEQ ID NO:112) and/or LCDR2 (DTSKLAS; SEQ ID NO:5) and/or LCDR3 (QQWTTNPLT; SEQ ID NO:6). In certain embodiments, the humanized anti-α2β1 integrin antibodies have a heavy chain comprising HCDR1 (GFSLTNYGIH; SEQ ID NO:1) and/or HCDR2 (VIWARGFTNYNSALMS; SEQ ID NO:2) and/or HCDR3 (ANDGVYYAMDY; SEQ ID NO:3) and a light chain variable region comprising the amino acid sequence of LCDR1 (SANSSVNYIH; SEQ ID NO:4 or SAQSSVNYIH; SEQ ID NO:112) and/or LCDR2 (DTSKLAS; SEQ ID NO:5) and/or LCDR3 (QQWTTNPLT; SEQ ID NO:6). In other embodiments, the antibody comprises an amino acid sequence variant of one or more of such CDRs, which variant comprises one or more amino acid insertion(s) within or adjacent to a CDR residue and/or deletion(s) within or adjacent to a CDR residue and/or substitution(s) of CDR residue(s) (with substitution(s) being the preferred type of amino acid alteration for generating such variants).

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides methods of treating cancer selected from the group consisting of squamous cell cancer, lung cancer including small-cell lung cancer, non-small cell lung cancer, adenocarcinoma of the lung, and squamous carcinoma of the lung, cancer of the peritoneum, hepatocellular cancer, gastric or stomach cancer including gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, colorectal cancer, endometrial or uterine carcinoma, salivary gland carcinoma, kidney or renal cancer, liver cancer, prostate cancer, vulval cancer, thyroid cancer, hepatic carcinoma and various types of head and neck cancer, as well as B-cell lymphoma including low grade/follicular non-Hodgkin's lymphoma (NHL); small lymphocytic (SL) NHL; intermediate grade/follicular NHL; intermediate grade diffuse NHL; high grade immunoblastic NHL; high grade lymphoblastic NHL; high grade small non-cleaved cell NHL; bulky disease NHL; mantle cell lymphoma; AIDS-related lymphoma; and Waldenstrom's Macroglobulinemia; chronic lymphocytic leukemia (CLL); acute lymphoblastic leukemia (ALL); Hairy cell leukemia; chronic myeloblastic leukemia; and post-transplant lymphoproliferative disorder (PTLD), as well as abnormal vascular proliferation associated with phakomatoses, edema such as that associated with brain tumors, Meigs' syndrome, melanoma, mesothelioma, multiple myeloma, fibrosarcoma, osteosarcoma, and epidermoid carcinoma using antibodies specifically reactive with human alpha 2 (α2) integrin, including humanized antibodies. The humanized antibodies may have human framework regions (FWs) and complementarity determining regions (CDRs) from a non-human antibody, typically a mouse, specifically reactive with human α2 integrin. In preferred embodiments, one or more of the CDR regions are derived from or based on the murine antibody secreted by the BHA2.1 hybridoma (Hangan et al., Cancer Res., 56(13): 3142-9 (1996)). This antibody binds to human and rat α2β1 integrin, but does not bind the murine counterpart. The antibody so produced by the BHA2.1 hybridoma is referred to herein as TMC-2206 and is commercially available from Chemicon (now part of Millipore, catalog number MAB1998). Further provided are methods of treating cancer selected from the group consisting of squamous cell cancer, lung cancer including small-cell lung cancer, non-small cell lung cancer, adenocarcinoma of the lung, and squamous carcinoma of the lung, cancer of the peritoneum, hepatocellular cancer, gastric or stomach cancer including gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, colorectal cancer, endometrial or uterine carcinoma, salivary gland carcinoma, kidney or renal cancer, liver cancer, prostate cancer, vulval cancer, thyroid cancer, hepatic carcinoma and various types of head and neck cancer, as well as B-cell lymphoma including low grade/follicular non-Hodgkin's lymphoma (NHL); small lymphocytic (SL) NHL; intermediate grade/follicular NHL; intermediate grade diffuse NHL; high grade immunoblastic NHL; high grade lymphoblastic NHL; high grade small non-cleaved cell NHL; bulky disease NHL; mantle cell lymphoma; AIDS-related lymphoma; and Waldenstrom's Macroglobulinemia; chronic lymphocytic leukemia (CLL); acute lymphoblastic leukemia (ALL); Hairy cell leukemia; chronic myeloblastic leukemia; and post-transplant lymphoproliferative disorder (PTLD), as well as abnormal vascular proliferation associated with phakomatoses, edema such as that associated with brain tumors, Meigs' syndrome, melanoma, mesothelioma, multiple myeloma, fibrosarcoma, osteosarcoma, and epidermoid carcinoma using antibodies having similar binding properties and antibodies (or other antagonists) having similar functionality as the antibodies disclosed herein. Preferred anti-α2 integrin antibodies include those that (a) bind to the I domain of α2 integrin, (b) inhibit the function of α2 integrin (e.g., collagen or laminin binding), (c) bind to α2 integrin on resting platelets without inducing platelet activation and (d) recognize the binding epitope of TMC-2206 (e.g., compete with TMC-2206 for the binding to α2 integrin). Such antibodies may bind preferentially to the inactive or closed conformation of the target α2 integrin molecule without competing for the ligand binding site. Advantages of anti-α2 integrin antibodies as described herein that bind preferentially to the closed conformation of the α2β1 integrin and/or bind to α2β1 integrin without competing for the ligand binding site (e.g., are not a ligand mimetic) include preventing potential platelet activation, platelet aggregation, decreases in circulating platelet count and/or bleeding complications in a treated subject.

“Bleeding complications” as used herein refers to any adverse effect on blood levels and physiology, including platelet thrombotic responses, thrombocytopenia, increased time to clot, increased bleeding time and blood loss that limit therapeutic use of the anti-α2 integrin antibody.

β2β1 integrin is a molecule comprised of an α2 integrin subunit (see, e.g., SEQ ID NO:7, for DNA sequence and SEQ ID NO:8 for protein sequence of human α2) from the family of alpha integrins, and a β1 integrin subunit (see, e.g., SEQ ID NO:9 for DNA sequence and SEQ ID NO:10 protein sequence of human β1) from the family of beta integrins, and may be from any subject including a mammal, but preferably is from a human. The α2β1 integrin may be purified from any natural source, or may be produced synthetically (e.g., by use of recombinant DNA technology). The nucleic acid coding sequences for α2 integrin and for β1 integrin are described in Takada and Hemler J. Cell Biol. 109(1):397-407 (1989; GenBank submission X17033; subsequently updated to entry NM 002203) and Argraves, W. S. J. Cell. Biol. September 105(3)1183-90 (1987; Genbank submission X07979.1 and related sequences representing alternatively spliced variants), respectively.

The ‘I’ domain of the α2β1 integrin molecule refers to a region of this α2β1 integrin molecule within the α2 subunit, and is described, for example, in Kamata et al., J Biol. Chem. 269:9659-9663 (1994); Emsley et al., J. Biol. Chem. 272:28512 (1997) and Cell 101:47 (2000). The amino acid sequence of a human I domain of α2 integrin is shown as SEQ ID NO:11 (see also, e.g., SEQ ID NO: 107). The I domain of α2 integrin contains a MIDAS type of ligand binding site (Metal Ion Dependent Adhesion Site) which has a requirement and a specificity for a given divalent cation to support ligand binding. The amino acid sequences for an I domain of α2 integrin in rat is shown as SEQ ID NO:93 (see also, e.g., SEQ ID NO:113) and in mouse is shown as SEQ ID NO:94 (see also, e.g., SEQ ID NO:114). Cynomolgus monkey and rhesus monkey I domain sequences were cloned from the leukocyte fraction derived from whole blood and are provided in SEQ ID NO:103 (DNA), SEQ ID NO:171 (amino acid) for cynomolgus and SEQ ID NO:104 (DNA), SEQ ID NO:172 (amino acid) for rhesus, respectively.

A TMC-2206 (BHA2.1) epitope refers to a region of the I domain of human α2 integrin to which the TMC-2206 antibody binds. This epitope spans a region of 127 amino acids encompassing amino acid residues, K40, N73, Q89, Y93, R165, and N166, which contribute to binding and optionally, other amino acid residues of the α2 integrin I domain as described in WO2007/056858.

The term “cancer” refers to or describes the physiological condition in mammals that is typically characterized by unregulated cell growth. Included in this definition are benign and malignant cancers, metatstatic cancers as well as adenomas or adenocarcinomas. “Tumor” refers to all neoplastic cell growth and proliferation, whether malignant or benign, and all pre-cancerous and cancerous cells and tissues. “Benign tumor” or “benign cancer” refers to a tumor that remains localized at the site of origin and does not have the capacity to infiltrate, invade, or metastasize to a distant site. “Malignant tumor” refers to a tumor that invades and damages other tissues around them. Treatment of cancer refers to both therapeutic use and prophylactic or preventative use of the anti-α2 integrin antibodies described herein. Those in need of treatment include those already diagnosed with the cancer as well as those in which the onset of the disorder is to be prevented or delayed.

Cancers can be selected from the group consisting of squamous cell cancer, lung cancer including small-cell lung cancer, non-small cell lung cancer, adenocarcinoma of the lung, and squamous carcinoma of the lung, cancer of the peritoneum, hepatocellular cancer, gastric or stomach cancer including gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, colorectal cancer, endometrial or uterine carcinoma, salivary gland carcinoma, kidney or renal cancer, liver cancer, prostate cancer, vulval cancer, thyroid cancer, hepatic carcinoma and various types of head and neck cancer, as well as B-cell lymphoma including low grade/follicular non-Hodgkin's lymphoma (NHL); small lymphocytic (SL) NHL; intermediate grade/follicular NHL; intermediate grade diffuse NHL; high grade immunoblastic NHL; high grade lymphoblastic NHL; high grade small non-cleaved cell NHL; bulky disease NHL; mantle cell lymphoma; AIDS-related lymphoma; and Waldenstrom's Macroglobulinemia; chronic lymphocytic leukemia (CLL); acute lymphoblastic leukemia (ALL); Hairy cell leukemia; chronic myeloblastic leukemia; and post-transplant lymphoproliferative disorder (PTLD), as well as abnormal vascular proliferation associated with phakomatoses, edema such as that associated with brain tumors, Meigs' syndrome, melanoma, mesothelioma, and multiple myeloma. Cancers which are preferably treated using the anti-α2 integrin antibodies described herein are selected from the group consisting of breast cancer, colorectal cancer, rectal cancer, non-small cell lung cancer, non-Hodgkins lymphoma (NHL), renal cell cancer, prostate cancer, liver cancer, pancreatic cancer, soft-tissue sarcoma, kaposi's sarcoma, carcinoid carcinoma, head and neck cancer, melanoma, ovarian cancer, mesothelioma, and multiple myeloma. The cancerous conditions amendible for treatment of the invention include metastatic cancers. Thus even more preferred are cancers selected from the group consisting of breast cancer, colorectal cancer, rectal cancer, non-small cell lung cancer, non-Hodgkins lymphoma (NHL), renal cell cancer, prostate cancer, liver cancer, pancreatic cancer, soft-tissue sarcoma, kaposi's sarcoma, carcinoid carcinoma, head and neck cancer, melanoma, ovarian cancer, mesothelioma, multiple myeloma, metastatic colorectal and metastatic breast cancer. Particular preferred are cancers selected from the group consisting of non-small cell lung cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, breast cancer, colon cancer, colorectal cancer, kidney cancer, prostate cancer, mesothelioma, fibrosarcoma, osteosarcoma, epidermoid carcinoma, metastatic colorectal, metastatic prostate and metastatic breast cancer. More particular preferred are cancers selected from the group consisting of non-small cell lung cancer, pancreatic cancer, glioblastoma, liver cancer, breast cancer, colon cancer, colorectal cancer, kidney cancer, prostate cancer, mesothelioma, fibrosarcoma, metastatic colorectal, metastatic prostate and metastatic breast cancer. Even more particular preferred are cancers selected from the group consisting of pancreatic cancer, breast cancer, colon cancer, colorectal cancer, non-small cell lung cancer, fibrosarcoma, metastatic colorectal, and metastatic breast cancer. Most particular preferred are cancers selected from the group consisting of pancreatic cancer, breast cancer, colon cancer, colorectal cancer, non-small cell lung cancer, and fibrosarcoma. Most preferred are pancreatic cancer, breast cancer or metastatic breast cancer, with a particular preference to pancreatic cancer. “Breast cancer” as referred herein include mammary adenocarcinoma. The method of the present invention is particularly suitable for the treatment of vascularized tumors.

A subject, including for purposes of treatment, refers to any animal classified as a mammal, including humans, domestic and farm animals, and zoo, sports or pet animals such as dogs, horses, cats, cows etc. Preferably, the subject is a human.

The term antibody or immunoglobulin is used in the broadest sense, and covers monoclonal antibodies (including full length monoclonal antibodies), polyclonal antibodies, multispecific antibodies, and antibody fragments so long as they exhibit the desired biological activity. Antibody fragments comprise a portion of a full length antibody, generally an antigen binding or variable region thereof. Examples of antibody fragments include Fab, Fab′, F(ab′)₂, and Fv fragments, diabodies, linear antibodies, single-chain antibody molecules, single domain antibodies (e.g., from camelids), shark NAR single domain antibodies, and multispecific antibodies formed from antibody fragments. Antibody fragments can also refer to binding moieties comprising CDRs or antigen binding domains including, but not limited to, VH regions (V_(H), V_(H)-V_(H)), anticalins, PepBodies™, antibody-T-cell epitope fusions (Troybodies) or Peptibodies. “Antibody fragment” and “antigen binding fragment” have the same meaning and are equivalently used herein.

A monoclonal antibody refers to an antibody obtained from a population of substantially homogeneous antibodies, e.g., the individual antibodies comprising the population are identical except for possible naturally occurring mutations that may be present in minor amounts. Monoclonal antibodies are highly specific, being directed against a single antigenic site. Furthermore, in contrast to conventional (e.g., polyclonal) antibody preparations which typically include different antibodies directed against different determinants (e.g., epitopes) on an antigen, each monoclonal antibody is directed against at least a single determinant on the antigen. The modifier “monoclonal” indicates the character of the antibody as being obtained from a substantially homogeneous population of antibodies, and is not to be construed as requiring production of the antibody by any particular method. For example, monoclonal antibodies may be made by the hybridoma method first described by Kohler et al., Nature 256:495 (1975), or may be made by recombinant DNA methods (see, e.g., U.S. Pat. No. 4,816,567). Monoclonal antibodies may also be isolated from phage antibody libraries, for example, using the techniques described in Clackson et al., Nature 352:624-628 (1991) and Marks et al., J. Mol. Biol. 222:581-597 (1991). Monoclonal antibodies can also be isolated using the techniques described in U.S. Pat. Nos. 6,025,155 and 6,077,677 as well as U.S. Patent Application Publication Nos. 2002/0160970 and 2003/0083293 (see also, e.g., Lindenbaum, et al., Nucleic Acids Research 32 (21):0177 (2004)).

Monoclonal antibodies can include chimeric antibodies in which a portion of the heavy and/or light chain is identical with or homologous to corresponding sequences in antibodies derived from a particular species or belonging to a particular antibody class or subclass, while the remainder of the chain(s) is identical with or homologous to corresponding sequences in antibodies derived from another species or belonging to another antibody class or subclass, as well as fragments of such antibodies, so long as they exhibit the desired biological activity (see, e.g., U.S. Pat. No. 4,816,567; and Morrison et al., Proc. Natl. Acad Sci. USA 81: 6851-6855 (1984) for mouse-human chimeric antibodies).

A hypervariable region refers to the amino acid residues of an antibody which are responsible for antigen-binding. The hypervariable region comprises amino acid residues from a complementarity determining region or CDR (e.g., residues 24-34 (L1), 50-56 (L2) and 89-97 (L3) in the light chain variable domain and 31-35 (H1), 50-65 (H2) and 95-102 (H3) in the heavy chain variable domain; Kabat et al., Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, Md. (1991)) and/or those residues from a hypervariable loop (e.g., residues 26-32 (L1), 50-52 (L2) and 91-96 (L3) in the light chain variable domain and 26-32 (H1), 53-55 (H2) and 96-101 (H3) in the heavy chain variable domain; Chothia and Lesk J. Mol. Biol. 196: 901-917 (1987)). Framework or FR residues are those variable domain residues other than the hypervariable region residues. For antibodies described herein, the CDR and framework regions are identified based on the Kabat numbering system except that the CDR1 of the heavy chain is defined by Oxford Molecular's AbM definition as spanning residues 26 to 35. The Oxford Molecular's AbM antibody modeling software (http://people.cryst.cck.ac.uk/-ubc07s/) (Martin et al., Proc. Natl Acad. Sci. USA, 86, 9268-9272 (1989); Martin et al., Methods Enzymol., 203, 121-153 (1991); Pedersen et al., Immunomethods, 1, 126 (1992); and Rees et al., In Sternberg M. J. E. (ed.), Protein Structure Prediction. Oxford University Press, Oxford, 141-172. (1996)) combines the Kabat CDR and the Chothia hypervariable region numbering systems to define CDRs.

Humanized forms of non-human (e.g., murine) antibodies may be chimeric antibodies which contain minimal sequence derived from non-human immunoglobulin. For the most part, humanized antibodies are human immunoglobulins (recipient or acceptor antibody) in which hypervariable region residues of the recipient are replaced by hypervariable region residues from a non-human species (donor antibody) such as mouse, rat, rabbit or nonhuman primate having the desired specificity, affinity, and capacity. In addition, individual or groups of Fv framework region (FR) residues of the human immunoglobulin may be replaced by corresponding non-human residues. Furthermore, humanized antibodies may comprise residues which are not found in the recipient antibody or in the donor antibody. These modifications are made to further refine antibody performance. In general, the humanized antibody will comprise substantially all of at least one, and typically two, variable regions or domains, in which all or substantially all of the hypervariable loops correspond to those of a non-human immunoglobulin and all or substantially all of the FR regions are those of a human immunoglobulin sequence. The humanized antibody optionally also will comprise at least a portion of an immunoglobulin constant region (e.g., Fc), typically that of a human immunoglobulin (see, e.g., Queen et al., Proc. Natl. Acad. Sci. USA 86:10029 (1989), and Foote and Winter, J. Mol. Biol. 224: 487 (1992)).

Single-chain Fv or scFv antibody fragments may comprise the V_(H) and V_(L) regions or domains of antibody, wherein these domains are present in a single polypeptide chain. Generally, the Fv polypeptide further comprises a polypeptide linker between the V_(H) and V_(L) domains which enables the scFv to form the desired structure for antigen binding (for a review, see, e.g., Pluckthun in The Pharmacology of Monoclonal Antibodies, vol. 113, Rosenburg and Moore eds. Springer-Verlag, New York, pp. 269-315 (1994)).

Diabody refers to small antibody fragments with two antigen-binding sites, which fragments comprise a heavy chain variable domain (V_(H)) connected to a light chain variable domain (V_(L)) in the same polypeptide chain (V_(H)-V_(L)). By using a linker that is too short to allow pairing between the two domains on the same chain, the domains are forced to pair with the complementary domains of another chain and create two antigen-binding sites. Diabodies are described more fully in, for example, EP 404,097; WO 93/11161; and Hollinger et al., Proc. Natl. Acad. Sci. USA 90: 6444-6448 (1993).

Linear antibody refers to antibodies such as those described in Zapata et al., Protein Eng. 8(10): 1057-1062 (1995). Briefly, these antibodies comprise a pair of tandem Fd segments (V_(H)-C_(H)1-V_(H)-C_(H)1) which form a pair of antigen binding regions. Linear antibodies can be bispecific or monospecific.

An isolated antibody refers to one which has been identified and separated and/or recovered from a component of its natural environment. Contaminant components of its natural environment are materials which would interfere with diagnostic or therapeutic uses for the antibody, and may include enzymes, hormones, and other proteinaceous or nonproteinaceous solutes. In preferred embodiments, the antibody will be purified (1) to greater than 95% by weight of antibody as determined by the Lowry method, and most preferably more than 99% by weight, (2) to a degree sufficient to obtain at least 15 residues of N-terminal or internal amino acid sequence by use of a spinning cup sequenator, or (3) to homogeneity by SDS-PAGE under reducing or nonreducing conditions using Coomassie blue or, preferably, silver stain. Isolated antibody includes the antibody in situ within recombinant cells since at least one component of the antibody's natural environment will not be present. Ordinarily, however, isolated antibody will be prepared by at least one purification step.

An epitope tagged antibody refers to one wherein the antibody of the invention is fused to an epitope tag. The epitope tag polypeptide has enough residues to provide an epitope against which an antibody thereagainst can be made, yet is short enough such that it does not interfere with activity of the anti-α2β1 integrin antibody. The epitope tag preferably is sufficiently unique so that the antibody thereagainst does not substantially cross-react with other epitopes. Suitable tag polypeptides generally have at least 6 amino acid residues and usually between about 8-50 amino acid residues (preferably between about 9-30 residues). Examples include the flu HA tag polypeptide and its antibody 12CA5 (Field et al., Mol. Cell. Biol. 8: 2159-2165 (1988)); the c-myc tag and the 8F9, 3C7, 6E10, G4, B7 and 9E10 antibodies thereto (Evan et al., Mol. Cell. Biol. 5(12):3610-3616 (1985)); and the Herpes Simplex virus glycoprotein D (gD) tag and its antibody (Paborsky et al., Protein Engineering 3(6): 547-553 (1990)). In certain embodiments, the epitope tag is a salvage receptor binding epitope which is an epitope of the Fc region of an IgG molecule (e.g., IgG₁, IgG₂, IgG₃, or IgG₄) that is responsible for increasing the in vivo serum half-life of the IgG molecule.

A cytotoxic agent refers to a substance that inhibits or prevents the function of cells and/or causes destruction of cells. This can include radioactive isotopes (e.g., ¹³¹I, ¹²⁵I, ⁹⁰Y and ¹⁸⁶Re), chemotherapeutic agents, and toxins such as enzymatically active toxins of bacterial, fungal, plant or animal origin, or fragments thereof. A non-cytotoxic agent refers to a substance that does not inhibit or prevent function of cells and/or does not cause destruction of cells. A non-cytotoxic agent may include an agent that can be activated to become cytotoxic. A non-cytotoxic agent may include a bead, liposome, matrix or particle (see, e.g., U.S. Patent Publications 2003/0028071 and 2003/0032995 which are incorporated by reference herein). Such agents may be conjugated, coupled, linked or associated with an anti-α2β1 integrin antibody as described herein.

A chemotherapeutic agent refers to a chemical compound useful in the treatment of cancer. Examples of chemotherapeutic agents include but are not limited to Adriamycin, Doxorubicin, 5-Fluorouracil, Cytosine arabinoside (“Ara-C”), Cyclophosphamide, Thiotepa, Taxotere (docetaxel), Busulfan, Cytoxin, Taxol, Methotrexate, Cisplatin, Melphalan, Vinblastine, Bleomycin, Etoposide, Ifosfamide, Mitomycin C, Mitoxantrone, Vincreistine, Vinorelbine, Carboplatin, Teniposide, Daunomycin, Caminomycin, Aminopterin, Dactinomycin, Mitomycins, Esperamicins (see U.S. Pat. No. 4,675,187), Melphalan and other related nitrogen mustards.

A prodrug refers to a precursor or derivative form of a pharmaceutically active substance that is less cytotoxic to tumor cells compared to the parent drug and is capable of being enzymatically activated or converted into the more active parent form (see, e.g., Wilman, “Prodrugs in Cancer Chemotherapy” Biochemical Society Transactions, 14, pp. 375-382, 615th Meeting Belfast (1986) and Stella et al., “Prodrugs: A Chemical Approach to Targeted Drug Delivery,” Directed Drug Delivery, Borchardt et al., (ed.), pp. 247-267, Humana Press (1985). Prodrugs include, but are mot limited to, phosphate-containing prodrugs, thiophosphate-containing prodrugs, sulfate-containing prodrugs, peptide-containing prodrugs, D-amino acid-modified prodrugs, glycosylated prodrugs, β-lactam-containing prodrugs, optionally substituted phenoxyacetamide-containing prodrugs or optionally substituted phenylacetamide-containing prodrugs, 5-fluorocytosine and other 5-fluorouridine prodrugs which can be converted into the more active cytotoxic free drug. Examples of cytotoxic drugs that can be derivatized into a prodrug form can be those chemotherapeutic agents described above.

A label refers to a detectable compound or composition which is conjugated or coupled directly or indirectly to the antibody. The label may itself be detectable by itself (e.g., radioisotope labels or fluorescent labels) or, in the case of an enzymatic label, may catalyze chemical alteration of a substrate compound or composition which is detectable.

Solid phase refers to a non-aqueous matrix to which the antibody of the present invention can adhere. Examples of solid phases encompassed herein include those formed partially or entirely of glass (e.g., controlled pore glass), polysaccharides (e.g., agarose), polyacrylamides, polystyrene, polyvinyl alcohol and silicones. In certain embodiments, depending on the context, the solid phase can comprise the well of an assay plate; in others it is a purification column (e.g., an affinity chromatography column). This term also includes a discontinuous solid phase of discrete particles, such as those described in U.S. Pat. No. 4,275,149.

The terms “once every two weeks dosis regimen”, “once every two weeks dosing”, and “once every two weeks administration”, as used herein, refer to the time course of administering a substance (e.g., anti-α2 integrin antibody) to a subject to achieve a therapeutic objective (e.g., the treatment of a cancer). The once every two weeks dosing regimen is not intended to include a weekly dosing regimen. Preferably, the substance is administered every 9-19 days, more preferably, every 11-17 days, even more preferably, every 13-15 days, and most preferably, every 14 days.

A liposome refers to a small vesicle composed of various types of lipids, phospholipids and/or surfactant which is useful for delivery of a drug (such as the antibodies of the invention and, optionally, a chemotherapeutic agent) to a mammal. The components of the liposome are commonly arranged in a bilayer formation, similar to the lipid arrangement of biological membranes.

An isolated nucleic acid molecule refers to a nucleic acid molecule that is identified and separated from at least one contaminant nucleic acid molecule with which it is ordinarily associated in the natural source of the antibody nucleic acid. An isolated nucleic acid molecule is other than in the form or setting in which it is found in nature. Isolated nucleic acid molecules therefore are distinguished from the nucleic acid molecule as it exists in natural cells. However, an isolated nucleic acid molecule includes a nucleic acid molecule contained in cells that ordinarily express the antibody where, for example, the nucleic acid molecule is in a chromosomal location different from that of natural cells.

A viral vector refers to a vehicle for the transfer of a nucleic acid (e.g. DNA or RNA) to cells through viral infection or transduction. Examples of viral vectors include retroviruses, adenoviruses, pox viruses, and baculovirus.

A non-viral vector refers to a nucleic acid vehicle such as a CAN, plasmid or chromosome that is delivered to cells by non-viral methods such as electroporation, injections, and cationic reagent mediated transfection.

Expression control sequences refer to those DNA sequences necessary for the expression of an operably linked coding sequence in a particular host organism. The control sequences that are suitable for prokaryotes, for example, include a promoter, optionally an operator sequence, and a ribosome binding site. Eukaryotic cells are known to utilize promoters, polyadenylation signals, and enhancers.

A nucleic acid is operably linked when it is placed into a functional relationship with another nucleic acid sequence. For example, DNA for a presequence or secretory leader is operably linked to DNA for a polypeptide if it is expressed as a preprotein that participates in the secretion of the polypeptide; a promoter or enhancer is operably linked to a coding sequence if it affects the transcription of the sequence; or a ribosome binding site is operably linked to a coding sequence if it is positioned so as to facilitate translation. Generally, operably linked DNA sequences are contiguous, and, in the case of a secretory leader, contiguous and in reading phase. However, enhancers do not have to be contiguous. Linking is accomplished by ligation at convenient restriction sites. If such sites do not exist, the synthetic oligonucleotide adaptors or linkers are used in accordance with conventional practice.

Cell, cell line, and cell culture are often used interchangeably and all such designations include progeny. Transformants and transformed cells (e.g., obtained by transfection, transformation or transduction of nucleic acids, vectors, virus, etc.) include the primary subject cell and cultures derived therefrom without regard for the number of transfers. It is also understood that all progeny may not be precisely identical in DNA content, due to deliberate or inadvertent mutations. Mutant progeny that have the same function or biological activity as screened for in the originally transformed cell are included. Where distinct designations are intended, it will be clear from the context.

Humanized antibodies as described herein include antibodies that have variable region frameworks derived from a human acceptor antibody molecule, hypervariable or CDR sequences from a donor murine antibody, and constant regions, if present, derived from human sequences.

Humanized antibodies used in the present invention have been constructed comprising CDRs from both the heavy chain variable and light chain variable regions of the murine monoclonal antibody clone BHA2.1 (Hangan et al., Cancer Res. 56:3142-3149 (1996)). Preferred starting materials for constructing antibodies are anti-α2 integrin antibodies such as those secreted by the BHA2.1 hybridoma (e.g., TMC-2206) that are function-blocking antibodies directed against human α2 integrin and are dependent for binding and activity on the presence of an intact I-domain within the targeted α2 integrin. Preferred are humanized antibodies with the epitope specificity of TMC-2206 (or BHA2.1), including antibodies which bind to the inactive conformation of the α2 integrin molecule, and/or do not act as ligand mimetics. Preferred are humanized antibodies with the epitope specificity of TMC-2206 (or BHA2.1) that, although they interact with α2β1 integrin present on both leukocytes and platelets, do not cause platelet activation, impair aggregation of activated platelets on collagen, have minimal or no effect on bleeding and/or are not associated with bleeding complications at administered concentrations, including therapeutic doses in vivo.

Antibodies may be constructed wherein the human acceptor molecule for the light chain variable region is selected based on homology considerations between potential acceptor molecule variable regions and with the light chain variable region of the murine antibody. Germline candidate human acceptor molecules are preferred to reduce potential antigenicity. Germline databases are made up of antibody sequences that read through the end of the heavy chain FW3 region and partially into the CDR3 sequence. For selection of a FW4 region, it is preferred to search databases of mature antibody sequences which have been derived from the selected germline molecule, and also preferred to select a reasonably homologous FW4 region for use in the recombinant antibody molecule. Human acceptor molecules are preferably selected from the same light chain class as the murine donor molecule, and of the same canonical structural class of the variable region of the murine donor molecule. Secondary considerations for selection of the human acceptor molecule for the light chain variable region include homology in CDR length between the murine donor molecule and the human acceptor molecule. Human acceptor antibody molecules are preferably selected by homology searches to the V-BASE database, and other databases such as the Kabat and the public NCBI databases may be used as well. For humanized anti-α2 integrin antibodies with the same or similar epitope specificity and/or functional properties as TMC-2206, a preferred light chain human acceptor molecule is SEQ ID NO:37 with the germline antibody sequence A14 for the FW 1-3 region and the sequence FGQGTKVEIK for FW4 (SEQ ID NO:38) which represents a common FW-4 of mature kappa 1 light chains (e.g., light chain sequence AAB24132 (NCBI entry gi/259596/gb/AAB24132).

Antibodies may be constructed wherein the human acceptor molecule for the heavy chain variable region is selected based on homology considerations between potential acceptor molecule variable regions and the heavy chain variable region of the murine antibody. Germline candidate human acceptor molecules are preferred to reduce potential antigenicity. Germline databases are made up of antibody sequences that read through the end of the heavy chain FW3 region and partially into the CDR3 sequence. For selection of a FW4 region, it is preferred to search databases of mature antibody sequences which have been derived from the selected germline molecule, and also preferred to select a reasonably homologous FW4 region for use in the recombinant antibody molecule. Human acceptor molecules are preferably selected from the same heavy chain class as the murine donor molecule, and of the same canonical structural class of the variable region of the murine donor molecule. Secondary considerations for selection of the human acceptor molecule for the heavy chain variable region include homology in CDR length between the murine donor molecule and the human acceptor molecule. Human acceptor antibody molecules are preferably selected by homology search to the V-BASE database, although other databases such as the Kabat and the public NCBI databases may be used as well. For anti-α2 integrin antibodies with the same or similar epitope specificity and/or functional properties as TMC-2206, a preferred heavy chain acceptor molecule is SEQ ID NO:39 with the germline antibody sequence 4-59 for the FW 1-3 region (SEQ ID NO:12) and antibody, CAA48104.1 (NCBI entry, gi/33583/emb/CAA48104.1) a mature antibody derived from the 4-59 germline sequence for the FW 4 region (SEQ ID NO:13) (http://www.ncbi.nlm.nih.gov).

Methods for humanizing a nonhuman α2 integrin antibody are known to the skilled person and are described e.g. in WO2007/056858. In order to humanize an anti-α2 integrin antibody, the nonhuman antibody starting material is obtained, including by preparation from immunization or by purchase of commercially available antibodies. Exemplary techniques for generating antibodies used in the present invention are described in WO2007/056858.

The α2β1 integrin antigen to be used for production of antibodies may be, for example, a soluble form of α2β1 integrin or other fragment of α2β1 integrin (e.g., an α2β1 integrin fragment comprising a human α2 integrin I-domain (SEQ ID NO:11); see also, e.g., SEQ ID NO: 107). Other forms of α2 integrin useful for generating antibodies will be apparent to those skilled in the art based on the sequence of α2 integrin (e.g., a human α2 integrin as in SEQ ID NO:8).

Polyclonal antibodies are preferably raised in animals by multiple subcutaneous (sc), intravenous (iv) or intraperitoneal (ip) injections of the relevant antigen with or without an adjuvant. It may be useful to conjugate the relevant antigen to a protein that is immunogenic in the species to be immunized, e.g., keyhole limpet hemocyanin, serum albumin, bovine thyroglobulin, or soybean trypsin inhibitor using a bifunctional or derivatizing agent, for example, maleimidobenzoyl sulfosuccinimide ester (conjugation through cysteine residues), N-hydroxysuccinimide (through lysine residues), glutaraldehyde, succinic anhydride, SOCl₂, or R¹N═C═NR, where R and R¹ are different alkyl groups.

Animals may be immunized against the antigen, immunogenic conjugates, or derivatives by combining the antigen or conjugate (e.g., 100 μg for rabbits or 5 μg for mice) with 3 volumes of Freund's complete adjuvant and injecting the solution intradermally at multiple sites. One month later the animals are boosted with the antigen or conjugate (e.g., with ⅕ to 1/10 of the original amount used to immunize) in Freund's complete adjuvant by subcutaneous injection at multiple sites. Seven to 14 days later the animals are bled and the serum is assayed for antibody titer. Animals are boosted until the titer plateaus. Preferably, for conjugate immunizations, the animal is boosted with the conjugate of the same antigen, but conjugated to a different protein and/or through a different cross-linking reagent. Conjugates also can be made in recombinant cell culture as protein fusions. Also, aggregating agents such as alum are suitably used to enhance the immune response.

Monoclonal antibodies may be made using the hybridoma method first described by Kohler et al., Nature, 256: 495 (1975), or may be made by recombinant DNA methods (e.g., U.S. Pat. No. 6,204,023). Monoclonal antibodies may also be made using the techniques described in U.S. Pat. Nos. 6,025,155 and 6,077,677 as well as U.S. Patent Application Publication Nos. 2002/0160970 and 2003/0083293 (see also, e.g., Lindenbaum, et al., Nucleic Acids Research 32 (21):0177 (2004)).

In the hybridoma method, a mouse or other appropriate host animal, such as a rat, hamster or monkey, is immunized (e.g., as hereinabove described) to elicit lymphocytes that produce or are capable of producing antibodies that will specifically bind to the antigen used for immunization. Alternatively, lymphocytes may be immunized in vitro. Lymphocytes then are fused with myeloma cells using a suitable fusing agent, such as polyethylene glycol, to form a hybridoma cell (see, e.g., Goding, Monoclonal Antibodies: Principles and Practice, pp. 59-103 (Academic Press, 1986)).

The hybridoma cells thus prepared are seeded and grown in a suitable culture medium that preferably contains one or more substances that inhibit the growth or survival of the unfused, parental myeloma cells. For example, if the parental myeloma cells lack the enzyme hypoxanthine guanine phosphoribosyl transferase (HGPRT or HPRT), the culture medium for the hybridomas typically will include hypoxanthine, aminopterin, and thymidine (HAT medium), which substances prevent the growth of HGPRT-deficient cells.

Preferred myeloma cells are those that fuse efficiently, support stable high-level production of antibody by the selected antibody-producing cells, and are sensitive to a medium such as HAT medium. Among these, preferred myeloma cell lines are murine myeloma lines, such as those derived from MOP-21 and M.C.-11 mouse tumors available from the Salk Institute Cell Distribution Center, San Diego, Calif. USA, and SP-2 or X63-Ag8-653 cells available from the American Type Culture Collection, Rockville, Md. USA. Human myeloma and mouse-human heteromyeloma cell lines also have been described for the production of human monoclonal antibodies (e.g., Kozbor, J. Immunol., 133: 3001 (1984); Brodeur et al., Monoclonal Antibody Production Techniques and Applications, pp. 51-63 (Marcel Dekker, Inc., New York, 1987)).

Culture medium in which hybridoma cells are growing is assayed for production of monoclonal antibodies directed against the antigen. Preferably, the binding specificity of monoclonal antibodies produced by hybridoma cells is determined by immunoprecipitation or by an in vitro binding assay, such as radioimmunoassay (RIA) or enzyme-linked immunoabsorbent assay (ELISA).

The binding affinity of the monoclonal antibody can be determined, for example, by the Scatchard analysis of Munson et al., Anal. Biochem., 107: 220 (1980).

After hybridoma cells are identified that produce antibodies of the desired specificity, affinity, and/or activity, the clones may be subcloned by limiting dilution procedures and grown by standard methods (Goding, Monoclonal Antibodies: Principles and Practice, pp. 59-103 (Academic Press, 1986)). Suitable culture media for this purpose include, for example, D-MEM or RPMI-1640 medium. In addition, the hybridoma cells may be grown in vivo as ascites tumors in an animal.

The monoclonal antibodies secreted by the subclones are suitably separated from the culture medium, ascites fluid, or serum by conventional immunoglobulin purification procedures including, for example, protein A chromatography, hydrophobic interaction chromatography, hydroxylapatite chromatography, gel electrophoresis, dialysis, and/or affinity chromatography.

DNA encoding the monoclonal antibodies is readily isolated and sequenced using conventional procedures (e.g., by using oligonucleotide probes that are capable of binding specifically to genes encoding the heavy and light chains of the monoclonal antibodies). The hybridoma cells serve as a preferred source of such DNA. Once isolated, the DNA may be placed into expression vectors, which are then transfected into host cells such as E. coli cells, simian COS cells, Chinese hamster ovary (CHO) cells, or myeloma cells, including those that do not otherwise produce immunoglobulin protein, to obtain the synthesis of monoclonal antibodies in the recombinant host cells. Recombinant production of antibodies is described in further detail below.

In certain embodiments, it may be desirable to generate amino acid sequence variants of the humanized antibody, particularly where these improve the binding affinity or other biological properties of the humanized antibody.

Amino acid sequence variants of humanized anti-α2β1 integrin antibody are prepared by introducing appropriate nucleotide changes into a humanized anti-α2β1 integrin antibody DNA, or by peptide synthesis. Such variants include, for example, deletions from, and/or insertions into and/or substitutions of, residues within the amino acid sequences shown for the anti-α2 integrin antibody TMC-2206 (e.g., derived from or based on variable region sequences as shown in SEQ ID NOS: 19 and 21). Any combination of amino acid deletion, insertion, and substitution is made to arrive at the final construct, provided that the final construct possesses the desired characteristics. The amino acid changes also may alter post-translational processes of the humanized anti-α2 integrin antibody, such as changing the number or position of glycosylation sites.

There are a number of methods used to make antibodies human or human-like (e.g., “humanization”). Approaches to humanize antibodies have varied over the years. One approach was to generate murine variable regions fused to human constant regions, so-called murine-human Fc chimeras (see, e.g., Morrison et al., Proc. Natl. Acad. Sci. USA 81:6851-6855 (1984); U.S. Pat. No. 5,807,715). Another approach exploited the fact that CDRs could be readily identified based on their hypervariable nature (Kabat et al, J. Biol. Chem. 252:6609-6616 (1977)), Kabat, Adv. Protein Chem. 32:1-75 (1978)) and canonical structure (Chothia and Lesk, J. Mol. Biol. 196(4):901-17 (1987); Lazakani et al., J. Mol. Biol. 272:929 (1997) and humanized by grafting just the non-human CDR regions (referred to as donor CDRs) onto a human framework (referred to as acceptor frameworks) as shown, for example by Jones et al., Nature 321(6069):522-5 (1986); (see, e.g., U.S. Pat. No. 5,225,539; U.S. Pat. No. 6,548,640). The six CDR loops are presented in a cluster, and based on crystallographic analysis, critical framework residues within the so-called “Vernier” zone flanking the CDRs or in the heavy-light chain interface can be readily identified (see, e.g., Chothia and Lesk, J. Mol. Biol. 196(4):901-17 (1987); Chothia et al., J. Mol. Biol. 186(3):651-63 (1985); Chothia et al., Nature 342(6252):877-83 (1989)). These residues can be back-mutated to the murine residue to restore the correct relative orientation of the six CDRs (see, e.g., Verhoyen et al., Science 239(4847):1534-6 (1988); Reichman et al., Nature 332(6162):323-7 (1988); Tempest et al., Biotechnology (NY) 9(3):266-71 (1991)). Since variable regions can be classified in families that bear relatively high homology between mouse and human (reviewed in e.g., Pascual and Capra Adv. Immunol. 49:1-74 (1991)), these early studies also indicated that the potential for loss in affinity could be minimized in the grafted antibody by selecting the human germline sequence with the highest homology to the murine antibody of interest for use as the human acceptor molecule (see, e.g., U.S. Pat. No. 5,225,539; Verhoyen et al., Science 239(4847):1534-6 (1988)).

Family homologies and structural relationships between frameworks that impact correct presentation of a given type of CDR canonical structure have been reported (see, e.g., Al-Lazakani et al., J. Mol. Biol. 273(4):927-48 (1997) and references therein). Preferably, a best fit human or germline sequence is chosen. Available databases of antibody germline sequences may be used to determine the family subtype of a given murine heavy and light chain and to identify best fit sequences useful as human acceptor frameworks within that human subfamily. Both the linear amino acid homology of the donor and acceptor frameworks as well as the CDR canonical structure are preferably taken into account.

Exemplary heavy chain residues which may be substituted in a humanized anti-α2 integrin antibody include any one or more of the following framework residue numbers: H37, H48, H67, H71, H73, H78 and H91 (Kabat numbering system). Preferably at least four of these framework residues are substituted. A particularly preferable set of substitutions for the heavy chain in humanized anti-α2 integrin antibodies as exemplified herein is H37, H71, H73 and H78. Similarly, residues in the light chain can also be substituted. Exemplary light chain residues for substitution include any one or more of the following residue numbers: L1, L2, L4, L6, L46, L47, L49 and L71. Preferably at least three of these framework residues are substituted. A particularly preferable set of substitutions for the light chain in humanized anti-α2 integrin antibodies as exemplified herein is L2, L46 and L49.

A useful method for identification of certain residues or regions of a humanized anti-α2 integrin antibody that are preferred locations for mutagenesis is called “alanine scanning mutagenesis” (see, e.g., Cunningham and Wells Science, 244: 1081-1085 (1989)). Here, a residue or group of target residues are identified (e.g., charged residues such as arg, asp, his, lys, and glu) and replaced by a neutral or negatively charged amino acid (preferably alanine or polyalanine) to affect the interaction of the amino acids with α2β1 integrin antigen. Those amino acid locations demonstrating functional sensitivity to the substitutions then are refined by introducing further or other variants at, or for, the sites of substitution. Thus, while the site for introducing an amino acid sequence variation is predetermined, the nature of the mutation per se need not be predetermined. For example, to analyze the performance of a mutation at a given site, ala scanning or random mutagenesis is conducted at the target codon or region and the expressed humanized anti-α2 integrin antibody variants are screened for the desired activity.

Amino acid sequence insertions include amino- and/or carboxyl-terminal fusions ranging in length from one residue to polypeptides containing a hundred or more residues, as well as intrasequence insertions of single or multiple amino acid residues. Examples of terminal insertions include a humanized anti-α2 integrin antibody with an N-terminal methionyl residue or the antibody fused to an epitope tag. Other insertional variants of a humanized anti-α2 integrin antibody molecule include the fusion to the N- or C-terminus of a humanized anti-α2 integrin antibody of an enzyme or a polypeptide which increases the serum half-life of the antibody (see below).

Another type of variant is an amino acid substitution variant. These variants have at least one amino acid residue in a humanized anti-α2 integrin antibody molecule removed and a different residue inserted in its place. The sites of greatest interest for substitutional mutagenesis include the hypervariable loops, but framework alterations are also contemplated. Hypervariable region residues or framework residues involved in antigen binding are generally substituted in a relatively conservative manner. Such conservative substitutions are shown below under the heading of “preferred substitutions”. If such substitutions result in a change in biological activity, then more substantial changes, denominated “exemplary substitutions” or as further described below in reference to amino acid classes, are introduced and the products screened.

Original Exemplary Preferred Residue Substitutions Substitutions Ala (A) val; leu; ile Val Arg (R) lys; gln; asn Lys Asn (N) gln; his; lys; arg Gin Asp (D) glu Glu Cys (C) ser Ser Gln (Q) asn Asn Glu (E) asp Asp Gly (G) pro; ala Ala His (H) asn; gln; lys; arg Arg Ile (I) leu; val; met; ala; Leu phe; norleucine Leu (L) norleucine; ile; val; Ile met; ala; phe Lys (K) arg; gln; asn Arg Met (M) leu; phe; ile leu Phe (F) leu; val; ile; ala; tyr Leu Pro (P) ala Ala Ser (S) thr Thr Thr (T) ser Ser Trp (W) tyr; phe Tyr Tyr (Y) trp; phe; thr; ser Phe Val (V) ile; leu; met; phe; Leu ala; norleucine

Substantial modifications in the biological properties of the antibody are accomplished by selecting substitutions that differ significantly in their effect on maintaining (a) the structure of the polypeptide backbone in the area of the substitution, for example, as a sheet or helical conformation, (b) the charge or hydrophobicity of the molecule at the target site, or (c) the bulk of the side chain. Naturally occurring residues are divided into groups based on common side-chain properties: (1) hydrophobic: norleucine, met, ala, val, leu, ile; (2) neutral hydrophilic: cys, ser, thr; (3) acidic: asp, glu; (4) basic: asn, gin, his, lys, arg; (5) residues that influence chain orientation: gly, pro; and (6) aromatic: trp, tyr, phe.

Non-conservative substitutions will entail exchanging a member of one of these classes for another class. Any cysteine residue not involved in maintaining the proper confirmation of a humanized anti-α2 integrin antibody also may be substituted, generally with serine, to improve the oxidative stability of the molecule and prevent aberrant crosslinking. Conversely, cysteine bond(s) may be added to the antibody to improve its stability (particularly where the antibody is an antibody fragment such as an Fv fragment).

Another type of amino acid variant of the antibody alters the original glycosylation pattern of the antibody. By altering is meant deleting one or more carbohydrate moieties found in the antibody and/or adding one or more glycosylation sites that are not present in the antibody.

Glycosylation of antibodies is typically either N-linked or O-linked. N-linked refers to the attachment of the carbohydrate moiety to the side chain of an asparagine residue. The tripeptide sequences asparagine-X-serine and asparagine-X-threonine, where X is any amino acid except proline, are the recognition sequences for enzymatic attachment of the carbohydrate moiety to the asparagine side chain. Thus, the presence of either of these tripeptide sequences in a polypeptide creates a potential glycosylation site. O-linked glycosylation refers to the attachment of one of the sugars N-aceylgalactosamine, galactose, or xylose to a hydroxyamino acid, most commonly serine or threonine, although 5-hydroxyproline or 5-hydroxylysine may also be used.

Addition or deletion of glycosylation sites to the antibody is conveniently accomplished by altering the amino acid sequence such that it contains or lacks one or more of the above-described tripeptide sequences (for N-linked glycosylation sites). The alteration may also be made by the addition of, substitution by, or deletion of, one or more serine or threonine residues to the sequence of the original antibody (for O-linked glycosylation sites). Nucleic acid molecules encoding amino acid sequence variants of humanized anti-α2 integrin antibody are prepared by a variety of methods known in the art. These methods include, but are not limited to, isolation from a natural source (in the case of naturally occurring amino acid sequence variants) or preparation by oligonucleotide-mediated (or site-directed) mutagenesis, PCR mutagenesis, or cassette mutagenesis of an earlier prepared variant or a non-variant version of humanized anti-α2 integrin antibody.

Ordinarily, amino acid sequence variants of a humanized anti-α2 integrin antibody will have an amino acid sequence having at least 75% amino acid sequence identity with the original humanized antibody amino acid sequences of either the heavy or the light chain (e.g., variable region sequences as in SEQ ID NO:21 or SEQ ID NO:19, respectively), more preferably at least 80%, more preferably at least 85%, more preferably at least 90%, and most preferably at least 95%, including for example, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 98%, 99%, and 100%. Identity or homology with respect to this sequence is 96%, 97%, defined herein as the percentage of amino acid residues in the candidate sequence that are identical with the humanized anti-α2 integrin residues, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity, and not considering any conservative substitutions (as described above) as part of the sequence identity. None of N-terminal, C-terminal, or internal extensions, deletions, or insertions into the antibody sequence shall be construed as affecting sequence identity or homology. Thus sequence identity can be determined by standard methods that are commonly used to compare the similarity in position of the amino acids of two polypeptides. Using a computer program such as BLAST or FASTA, two polypeptides are aligned for optimal matching of their respective amino acids (either along the full length of one or both sequences, or along a pre-determined portion of one or both sequences). The programs provide a default opening penalty and a default gap penalty, and a scoring matrix such as PAM250 (a standard scoring matrix; see Dayhoff et al., in Atlas of Protein Sequence and Structure, vol 5, supp. 3 (1978)) can be used in conjunction with the computer program. For example, the percent identity can the be calculated as: the total number of identical matches multiplied by 100 and then divided by the sum of the length of the longer sequence within the matched span and the number of gaps introduced into the longer sequences in order to align the two sequences.

Antibodies having the characteristics identified herein as being desirable in a humanized anti-α2 integrin antibody are screened for by methods as described herein. For example, methods for screening candidate anti-α2 integrin antibodies for preferred characteristics and functionalities are provided that include screening for antibodies which bind to the epitope on α2β1 integrin bound by an antibody of interest (e.g., those which compete with, inhibit or block binding of the TMC-2206 antibody to α2β1 integrin). Cross-blocking assays can be performed and are described, for example, in Antibodies, A Laboratory Manual, Cold Spring Harbor Laboratory, Ed Harlow and David Lane (1988). In addition, or alternatively, epitope mapping, for example, as described in Champe et al., J. Biol. Chem. 270:1388-1394 (1995), can be performed to determine whether the antibody binds an epitope of interest.

Immobilized α2β1 integrin can similarly be used to determine relative binding potencies by measuring K_(i) values in competition assays. For example, fluorescently labeled Eu-TMC-2206 is used in the presence of varying concentrations of unlabeled candidate antibody, for example, using an assay system similar to that described above. Following a specified incubation time, the amount of bound Eu-TMC-2206 is determined. The inhibition curves are fitted with the “one site competition” model using Prism software (GraphPad, Inc. CA) to obtain IC₅₀ values and to calculate the K_(i) using the equation of Cheng and Prusoff (Biochem, Pharmacol. 22(23):3099-108 (1973)).

It is desirable to prepare, identify and/or select humanized anti-α2 integrin antibodies which have beneficial binding properties, for example, under conditions as described in Example 2 of WO2007/056858, wherein candidate antibodies are tested for their ability to block α2β1-integrin mediated cell adhesion in comparison to TMC-2206 and the mouse-human chimeric antibody derived from TMC-2206. For example, CHO cells expressing human α2 integrin and endogenous hamster β1 (Symington et al., J. Cell Biol. 120(2):523-35 (1993)) are prepared and labeled with CFSE (Molecule Probes, OR). Labeled cells are prepared and the cell concentration is adjusted; cells are kept in the dark until used. A collagen-coated plate (rat-tail collagen Type I; BD Biosciences) is prepared and each serially diluted antibody solution is added to the collagen plate. Labeled cells are then added to the well and the plate is incubated. After washing, cells are lysed and the fluorescence intensity (excitation, 485 nm; emission, 535 nm) is read. The inhibitory activity of each antibody is calculated.

Additionally, binding constants of the candidate antibodies for the immobilized α2β1 integrin ligand can be calculated as described in Example 2 of WO2007/056858. Wells in a 96 well microtiter plate are coated with platelet α2β1-integrin (custom-coated with human platelet α2β1 by GTI Inc., WI) and then blocked. For example, to determine the affinity of TMC-2206 for its α2 integrin antigen, fluorescently labeled TMC-2206 or isotype control IgG antibody are used. The fluorescently labeled antibody, including Eu-TMC-2206 or Eu-isotype control IgG, is applied to the blocked α2β1-integrin microtiter plates. After incubating the sealed plates to allow the antibody-antigen interaction to reach equilibrium, samples are transferred from each well into a fresh well containing an enhancement solution for the measurement of free (unbound) label. The enhancement solution is also added to the emptied wells for the measurement of bound label. The K_(d) values of the anti-α2 integrin antibody is calculated by Scatchard analysis. The relative affinity of TMC-2206 derivatives (including humanized antibodies derived from or based on TMC-2206) can be determined by determining the Ki value in a competition assay. For example, for the competition assay, Eu-labelled TMC-2206 is added to α2β1-coated wells in the presence of unlabelled anti-α2 integrin antibodies, including TMC-2206 or chimeric (including humanized) antibodies derived from or based on TMC-2206, or isotype control IgG antibody at various concentrations. After a period of incubation to reach equilibrium, the wells are washed and the bound labeled antibody levels are measured as retained Eu label in each well. The Ki value can be derived from the EC50 values using the K_(d) value obtained for the Eu-TMC-2206 antibody by the direct binding studies as described above.

In certain embodiments, the humanized anti-α2 integrin antibody is an antibody fragment. Various techniques have been developed for the production of antibody fragments. Traditionally, these fragments were derived via proteolytic digestion of intact antibodies (see, e.g., Morimoto et al., Journal of Biochemical and Biophysical Methods 24: 107-117 (1992) and Brennan et al., Science 229: 81 (1985)). However, these fragments can be produced directly by recombinant host cells, such as bacteria (see, e.g., Better et al., Science 240(4855):1041-1043 (1988); U.S. Pat. No. 6,204,023. For example, Fab′-SH fragments can be directly recovered from E. coli and chemically coupled to form F(ab′)₂ fragments (Carter et al., Bio/Technology 10: 163-167 (1992)). According to another approach, F(ab′)₂ fragments can be isolated directly from recombinant host cell culture. Other techniques for the production of antibody fragments will be apparent to the skilled practitioner.

In some embodiments, it may be desirable to generate multispecific (e.g., bispecific) humanized anti-α2 integrin antibodies having binding specificities for at least two different epitopes. Exemplary bispecific antibodies (e.g., with two different binding arms) may bind to two different epitopes of the α2β1 integrin protein. Alternately, an anti-α2 integrin arm may be combined with an arm which binds to a triggering molecule on a leukocyte such as a T-cell receptor molecule (e.g., CD2 or CD3), or Fc receptors for IgG (FcγR), such as FcγRI (CD64), FcγRII (CD32) and FcγRIII (CD16) so as to focus cellular defense mechanisms on a cell which has α2β1 integrin bound to its surface. Bispecific antibodies can be used to localized cytotoxic agents to cells with α2β1 integrin bound to their surface. These antibodies possess a α2β1 integrin binding arm and an arm which binds the cytotoxic agent (e.g., gelonin, saporin, anti-interferon alpha, vinca alkaloid, ricin A chain, or radioisotope hapten). Bispecific antibodies can be prepared as full length antibodies or antibody fragments (e.g., F(ab′)₂ bispecific antibodies).

According to another approach for making bispecific antibodies, the interface between a pair of antibody molecules can be engineered to maximize the percentage of heterodimers which are recovered from recombinant cell culture. The preferred interface comprises at least a part of the CH3 domain of an antibody constant domain. In this method, one or more small amino acid side chains are replaced with larger side chains (e.g., tyrosine or tryptophan). Compensatory cavities of identical or smaller size to the large side chain(s) are created on the interface of the second antibody by replacing large amino acid side chains with smaller ones (e.g., alanine or threonine). This provides a mechanism for increasing the yield of the heterodimers over other unwanted end-products such as homodimers (see, e.g., WO96/27011).

Bispecific antibodies include cross-linked or heteroconjugate antibodies. For example, one of the antibodies in the heteroconjugate can be coupled to avidin, the other to biotin. Heteroconjugate antibodies may be made using any convenient cross-linking methods. Suitable cross-linking agents are well known in the art, and are disclosed, for example, in U.S. Pat. No. 4,676,980 along with a number of cross-linking techniques.

Techniques for generating bispecific antibodies from antibody fragments have also been described in the literature. Bispecific antibodies can be prepared using chemical linkage. For example, Brennan et al., (Science 229:81 (1985)) describe a procedure wherein intact antibodies are proteolytically cleaved to generate F(ab′)₂ fragments. These fragments are reduced in the presence of the dithiol complexing agent sodium arsenite to stabilize vincal dithiols and prevent intermolecular disulfide formation. The Fab′ fragments generated are then converted to thionitrobenzoate (TNB) derivatives. One of the Fab′-TNB derivatives is then reconverted to the Fab′-thiol by reduction with mercaptoethylamine and is mixed with an equimolar amount of the other Fab′-TNB derivative to form the bispecific antibody. The bispecific antibodies produced can be used as agents for the selective immobilization of enzymes.

Fab′-SH fragments, recovered from E. coli, can be chemically coupled to form bispecific antibodies. For example, Shalaby et al., (J. Exp. Med. 175:217-225 (1992)) describe the production of a fully humanized bispecific antibody F(ab′)₂ molecule. Where each Fab′ fragment was separately secreted from E. coli and subjected to directed chemical coupling in vitro to form the bispecific antibody. The bispecific antibody thus formed was able to bind to cells overexpressing the HER2 receptor and normal human T cells, as well as trigger the lytic activity of human cytotoxic lymphocytes against human breast tumor targets.

Various techniques for making and isolating bispecific antibody fragments directly from recombinant cell culture have also been described. For example, bispecific antibodies have been produced using leucine zippers (see, e.g., Kostgelny et al., J. Immunol. 148(5):1547-1553 (1992)). The leucine zipper peptides from the Fos and Jun proteins were linked to Fab′ portions of two different antibodies by gene fusion. The antibody homodimers were reduced at the hinge region to form monomers and then re-oxidized to form antibody heterodimers. This method can also be utilized for the production of antibody heterodimers. The diabody technology (see, e.g., Hollinger et al., Proc. Natl. Acad. Sci. USA 90:6444-6448 (1993) has provided an alternative mechanism for making bispecific antibody fragments. The fragments comprise a heavy chain variable region (VH) connected to a light-chain variable region (VL) by a linker which is too short to allow pairing between the two domains on the same chain. Accordingly, the VH and VL domains of one fragment are forced to pair with the complementary VL and VH domains of another fragment, thereby forming two antigen-binding sites. Another strategy for making bispecific antibody fragments by the use of single-chain Fv (sFv or scFv) dimers also has been reported (see, e.g., Gruber et al., J. Immunol. 152:5368 (1994)). Alternatively, the bispecific antibody, may be a linear antibody, for example, produced as described in Zapata et al., Protein Eng. 8(10):1057-1062 (1995).

Antibodies with more than two valencies are contemplated. For example, trispecific antibodies can be prepared (see, e.g., Tuft et al., J. Immunol. 147:60 (1991)).

Other modifications of the humanized anti-α2 integrin antibodies are contemplated. For example, it may be desirable to modify the antibody with respect to effector function, so as to enhance or decrease the effectiveness of the antibody, for example, in treating cancer. Cysteine residue(s) may be introduced in the Fc region, thereby allowing interchain disulfide bond formation in the region. The homodimeric antibody thus generated may have improved internalization capability and/or increased complement mediated cell killing (CMC) and/or antibody-dependent cellular cytotoxicity (ADCC) (see e.g., Caron et al., J. Exp. Med. 176:1191-1195 (1992) and Shopes, B. J. Immunol. 148:2918-2922 (1992)). Homodimeric antibodies with enhanced anti-tumor activity may also be prepared using heterobifunctional cross-linkers (see, e.g., those described in Wolff et al., Cancer Research 53:2560-2565 (1993)). Alternatively, an antibody can be engineered which has dual Fc regions and may thereby have enhanced CMC and/or ADCC capabilities (see, e.g., Stevenson et al., Anti-Cancer Drug Design 3:219-230 (1989)).

Immunoconjugates comprising a humanized anti-α2 integrin antibody conjugated to a moiety, e.g., a molecule, composition, complex, or agent, for example a cytotoxic agent such as a chemotherapeutic agent, toxin (e.g., an enzymatically active toxin of bacterial, fungal, plant or animal origin, or fragments thereof), or a radioactive isotope (e.g., a radioconjugate), for the targeting of the agent to an anti-α2 integrin-expressing cell, tissue or organ. Such an immunoconjugate may be used in a method of targeting the moiety or agent to a particular site of action characterized by the presence of α2 or α2β1 integrin.

Chemotherapeutic agents useful in the generation of such immunoconjugates have been described above. Enzymatically active toxins and fragments thereof which can be used include diphtheria A chain, nonbinding active fragments of diphtheria toxin, exotoxin A chain (from Pseudomonas aeruginosa), ricin A chain, abrin A chain, modeccin

A chain, alpha-sarcin, Aleurites fordii proteins, dianthin proteins, Phytolaca americana proteins (PAPI, PAPII, and PAP-S), momordica charantia inhibitor, curcin, crotin, sapaonaria officinalis inhibitor, gelonin, mitogellin, restrictocin, phenomycin, enomycin or the tricothecenes. A variety of radionuclides are available for the production of radioconjugated anti-alpha 2 integrin antibodies. Examples include ²¹²Bi, ¹³¹In, ⁹⁰Y or ¹⁸⁶Re.

Conjugates of the antibody and cytotoxic agent are made using a variety of bifunctional protein coupling agents such as N-succinimidyl-3-(2-pyridyldithiol) propionate (SPDP), iminothiolane (IT), bifunctional derivatives of imidoesters (such as dimethyl adipimidate HCL), active esters (such as disuccinimidyl suberate), aldehydes (such as gluteraldehyde), bis-azido compounds (such as bis(p-azidobenzoyl) hexanediamine), bis-diazonium derivatives (such as bis-(p-diazoniumbenzoyl)-ethylenediamine), diisocyanates (such as tolyene 2,6-diisocyanate), or bis-active fluorine compounds (such as 1,5-difluoro-2,4-dinitrobenzene). For example, a ricin immunotoxin can be prepared as described in Vitetta et al., Science 238:1098 (1987). Carbon-14-labeled 1-isothiocyanatobenzyl-3-methyldiethylene triaminepentaacetic acid (MX-DTPA) is an exemplary chelating agent for conjugation of radionuclide to the antibody (see, e.g., WO94/11026).

In another embodiment, the antibody may be conjugated to a receptor (such as streptavidin) for utilization in pretargeting α2 integrin-expressing cell, tissue or organ wherein the antibody-receptor conjugate is administered to the patient, followed by removal of unbound conjugate from the circulation using a clearing agent and then administration of a ligand (e.g., avidin) which is conjugated to an agent, for example a cytotoxic agent (e.g., a radio-nuclide).

The anti-α2 integrin antibodies disclosed herein may also be formulated as immunoliposomes. Liposomes containing the antibody are prepared by methods known in the art, such as described in Epstein et al., Proc. Natl. Acad. Sci. USA 82: 3688 (1985); Hwang et al., Proc. Natl. Acad. Sci. USA 77: 4030 (1980); and U.S. Pat. Nos. 4,485,045 and 4,544,545. Liposomes with enhanced circulation time are disclosed in U.S. Pat. No. 5,013,556.

Particularly useful liposomes can be generated by the reverse phase evaporation method with a lipid composition comprising phosphatidylcholine, cholesterol and PEG-derivatized phosphatidylethanolamine (PEG-PE). Liposomes are extruded through filters of defined pore size to yield liposomes with the desired diameter. Fab′ fragments of an anti-α2 integrin antibody can be conjugated to the liposomes as described in Martin et al., J. Bid. Chem. 257: 286-288 (1982) via a disulfide interchange reaction. A chemotherapeutic agent (e.g., doxorubicin) is optionally contained within the liposome (see, e.g., Gabizon et al., J. National Cancer Inst. 81(19): 1484 (1989)).

Humanized anti-α2 integrin antibodies may also be used in Antibody Directed Enzyme Prodrug Therapy (ADEPT) by conjugating the antibody to a prodrug-activating enzyme which converts a prodrug (e.g., a peptidyl chemotherapeutic agent, see, e.g., WO81/01145) to an active drug. (see, e.g., WO88/07378 and U.S. Pat. No. 4,975,278). The enzyme component of the immunoconjugate useful for ADEPT includes any enzyme capable of acting on a prodrug in such a way so as to covert it into its more active form. Enzymes that are useful include, but are not limited to, alkaline phosphatase useful for converting phosphate-containing prodrugs into free drugs; arylsulfatase useful for converting sulfate-containing prodrugs into free drugs; cytosine deaminase useful for converting non-toxic 5-fluorocytosine into the anti-cancer drug, 5-fluorouracil; proteases, such as serratia protease, thermolysin, subtilisin, carboxypeptidases and cathepsins (such as cathepsins B and L), that are useful for converting peptide-containing prodrugs into free drugs; D-alanylcarboxypeptidases, useful for converting prodrugs that contain D-amino acid substituents; carbohydrate-cleaving enzymes such as β-galactosidase and neuraminidase useful for converting glycosylated prodrugs into free drugs; β-lactamase useful for converting drugs derivatized with β-lactams into free drugs; and penicillin amidases, such as penicillin V amidase or penicillin G amidase, useful for converting drugs derivatized at their amine nitrogens with phenoxyacetyl or phenylacetyl groups, respectively, into free drugs. Alternatively, antibodies with enzymatic activity, also known as abzymes, can be used to convert the prodrugs of the invention into free active drugs (see, e.g., Massey, Nature 328: 457-458 (1987)). Antibody-abzyme conjugates can be prepared as described herein, including for delivery of the abzyme to a α2 integrin-expressing cell, tissue or organ.

Enzymes may be covalently bound to the anti-α2 integrin antibodies by techniques well known in the art, including the use of the heterobifunctional crosslinking reagents discussed above. Alternatively, fusion proteins comprising at least the antigen binding region of an anti-α2 integrin antibody linked to at least a functionally active portion of an enzyme can be constructed using recombinant DNA techniques well known in the art (see, e.g., Neuberger et al., Nature 312: 604-608 (1984)).

In certain embodiments of the invention, it may be desirable to use an antibody fragment, rather than an intact antibody, for example, to increase tissue or tumor penetration. It may also be desirable to modify the antibody fragment in order to increase its serum half-life. This may be achieved by incorporation of a salvage receptor binding epitope into the antibody fragment, for example, by mutation of the appropriate region in the antibody fragment or by incorporating the epitope into a peptide tag that is then fused to the antibody fragment at either end or in the middle, for example, by DNA or peptide synthesis (see, e.g., WO96/32478).

Covalent modifications of the humanized anti-α2 integrin antibodies may be made, for example, by chemical synthesis or by enzymatic or chemical cleavage of the antibody. Other types of covalent modifications of the antibody are introduced into the molecule by reacting targeted amino acid residues of the antibody with an organic derivatizing agent that is capable of reacting with selected side chains or the N- or C-terminal residues. Cysteinyl residues, for example, most commonly are reacted with α-haloacetates (and corresponding amines), such as chloroacetic acid or chloroacetamide, to give carboxymethyl or carboxyamidomethyl derivatives. Cysteinyl residues also are derivatized by reaction with bromotrifluoroacetone, α-bromo-β-(5-imidozoyl)propionic acid, chloroacetyl phosphate, N-alkylmaleimides, 3-nitro-2-pyridyl disulfide, methyl 2-pyridyl disulfide, p-chloromercuribenzoate, 2-chloromercuri-4-nitrophenol, or chloro-7-nitrobenzo-2-oxa-1,3-diazole. Histidyl residues, for example, are derivatized by reaction with diethylpyrocarbonate at pH 5.5-7.0 because this agent is relatively specific for the histidyl side chain. Para-bromophenacyl bromide also is useful; the reaction is preferably performed in 0.1 M sodium cacodylate at pH 6.0. Lysinyl and amino-terminal residues, for example, are reacted with succinic or other carboxylic acid anhydrides. Derivatization with these agents has the effect of reversing the charge of the lysinyl residues. Other suitable reagents for derivatizing α-amino-containing residues include imidoesters such as methyl picolinimidate, pyridoxal phosphate, pyridoxal, chloroborohydride, trinitrobenzenesulfonic acid, O-methylisourea, 2,4-pentanedione, and transaminase-catalyzed reaction with glyoxylate. Arginyl residues, for example, are modified by reaction with one or several conventional reagents, among them phenylglyoxal, 2,3-butanedione, 1,2-cyclohexanedione, and ninhydrin. Derivatization of arginine residues requires that the reaction be performed in alkaline conditions because of the high pK_(a) of the guanidine functional group. Furthermore, these reagents may react with the groups of lysine as well as the arginine epsilon-amino group. Tyrosyl residues, for example, are specifically modified with particular interest in introducing spectral labels into tyrosyl residues by reaction with aromatic diazonium compounds or tetranitromethane. Most commonly, N-acetylimidizole and tetranitromethane are used to form O-acetyl tyrosyl species and 3-nitro derivatives, respectively. Tyrosyl residues are iodinated using ¹²⁵I or ¹³¹I to prepare labeled proteins for use in radioimmunoassay. Carboxyl side groups, for example, aspartyl or glutamyl, are selectively modified by reaction with carbodiimides (R—N═C═N—R′), where R and R′ are different alkyl groups, such as 1-cyclohexyl-3-(2-morpholinyl-4-ethyl) carbodiimide or 1-ethyl-3-(4-azonia-4,4-dimethylpentyl) carbodiimide. Furthermore, aspartyl and glutamyl residues are converted to asparaginyl and glutaminyl residues by reaction with ammonium ions. Glutaminyl and asparaginyl residues are frequently deamidated to the corresponding glutamyl and aspartyl residues, respectively. These residues are deamidated under neutral or basic conditions. The deamidated form of these residues falls within the scope of this invention. Other modifications include hydroxylation of praline and lysine, phosphorylation of hydroxyl groups of seryl or threonyl residues, methylation of the α-amino groups of lysine, arginine, and histidine side chains (T. E. Creighton, Proteins: Structure and Molecular Properties, W.H. Freeman & Co., San Francisco, pp. 79-86 (1983)), acetylation of the N-terminal amine, and amidation of any C-terminal carboxyl group.

Another type of covalent modification involves chemically or enzymatically coupling glycosides to the antibody. These procedures are advantageous in that they do not require production of the antibody in a host cell that has glycosylation capabilities for N- or O-linked glycosylation. Depending on the coupling mode used, the sugar(s) may be attached to (a) arginine and histidine, (b) free carboxyl groups, (c) free sulfhydryl groups such as those of cysteine, (d) free hydroxyl groups such as those of serine, threonine, or hydroxyproline, (e) aromatic residues such as those of phenylalanine, tyrosine, or tryptophan, or (f) the amide group of glutamine (see, e.g., WO87/05330; Aplin and Wriston, CRC Grit. Rev. Biochem., pp. 259-306 (1981)).

Removal of any carbohydrate moieties present on the antibody may be accomplished, for example, chemically or enzymatically. Chemical deglycosylation requires exposure of the antibody to the compound trifluoromethanesulfonic acid, or an equivalent compound. This treatment results in the cleavage of most or all sugars except the linking sugar (N-acetylglucosamine or N-acetylgalactosamine), while leaving the antibody intact (see, e.g., Hakimuddin, et al., Arch. Biochem. Biophys. 259: 52 (1987); Edge et al., Anal. Biochem., 118: 131 (1981)). Enzymatic cleavage of carbohydrate moieties on antibodies can be achieved by the use of a variety of endo- and exo-glycosidases, (see, e.g., Thotakura et al., Meth. Enzymol. 138: 350 (1987)).

Another type of covalent modification of the antibody comprises linking the antibody to one of a variety of nonproteinaceous polymers, such as polyethylene glycol, polypropylene glycol, or polyoxyalkylenes (see, e.g., U.S. Pat. No. 4,640,835; 4,496,689; 4,301,144; 4,670,417; 4,791,192 or 4,179,337).

For recombinant production of the antibody, the nucleic acid(s) encoding the antibody are isolated and inserted into a replicable vector for further cloning (amplification of the DNA) or for expression. DNA encoding the antibody is readily isolated and sequenced using conventional procedures (e.g., by using oligonucleotide probes that are capable of binding specifically to genes encoding the heavy and light chains of the antibody). Many vectors are available. The vector components generally include, but are not limited to, one or more of the following: a signal sequence, an origin of replication, one or more marker genes, an enhancer element, a promoter, and a transcription termination sequence.

An anti-α2 integrin antibody may be produced recombinantly, including as a fusion polypeptide with a heterologous polypeptide, which is preferably a signal sequence or other polypeptide having a specific cleavage site at the N-terminus of the mature protein or polypeptide. The heterologous signal sequence selected preferably is one that is recognized and processed (e.g., cleaved by a signal peptidase) by the host cell. For prokaryotic host cells that do not recognize and process a eukaryotic signal sequence (e.g., an immunoglobulin signal sequence), the signal sequence is substituted by a prokaryotic signal sequence including, for example, pectate lysase (such as pelB), alkaline phosphatase, penicillinase, Ipp, or heat-stable enterotoxin II leaders. For yeast secretion, a yeast signal sequence may be utilized, including, for example, the yeast invertase leader, a factor leader (including Saccharomyces and Kluyveromyces α-factor leaders), or acid phosphatase leader, the C. albicans glucoamylase leader, or the signal described in WO90/13646. In mammalian cell expression, mammalian signal sequences as well as viral secretory leaders, for example, the herpes simplex gD signal, are available and may be utilized. The DNA for such a precursor region (e.g., the signal sequence) is ligated in reading frame to DNA encoding an anti-α2 integrin antibody.

Both expression and cloning vectors contain a nucleic acid sequence that enables the vector to replicate in one or more selected host cells. Generally, in cloning vectors, this sequence is one that enables the vector to replicate independently of the host chromosomal DNA, and includes origins of replication or autonomously replicating sequences. Such sequences are well known for a variety of bacteria, yeast, and viruses. For example, the origin of replication from the plasmid pBR322 is suitable for most gram-negative bacteria, the 2μ plasmid origin is suitable for yeast, and various viral origins (SV40, polyoma, adenovirus, VSV or BPV) are useful for cloning vectors in mammalian cells. Generally, the origin of replication component is not needed for mammalian expression vectors (e.g., the SV40 origin may typically be used only because it contains the early promoter).

Expression and cloning vectors may contain a selection gene, also termed a selectable marker. Typical selection genes encode proteins that (a) confer resistance to antibiotics or other toxins, e.g., ampicillin, neomycin, methotrexate, or tetracycline, (b) complement auxotrophic deficiencies, or (c) supply critical nutrients not available from complex media, (e.g., the gene encoding D-alanine racemase for Bacilli).

One example of a selection scheme utilizes a drug to arrest growth of a host cell. Those cells that are successfully transformed with a heterologous gene produce a protein conferring drug resistance and thus survive the selection regimen. Examples of such dominant selection use the drugs methotrexate, neomycin, histidinol, puromycin, mycophenolic acid and hygromycin.

Another example of suitable selectable markers for mammalian cells are those that enable the identification of cells competent to take up the anti-α2 integrin antibody nucleic acid, such as DHFR, thymidine kinase, metallothionein-I and -II, preferably primate metallothionein genes, adenosine deaminase, ornithine decarboxylase, etc.

For example, cells transformed with the DHFR selection gene are first identified by culturing all of the transformants in a culture medium that contains methotrexate (Mtx), a competitive antagonist of DHFR. An appropriate host cell when wild-type DHFR is employed is the Chinese hamster ovary (CHO) cell line deficient in DHFR activity.

Alternatively, host cells (particularly wild-type hosts that contain endogenous DHFR) transformed or co-transformed with DNA sequences encoding anti-α2 integrin antibody, wild-type DHFR protein, and another selectable marker such as aminoglycoside 3′-phosphotransferase (APH) can be selected by cell growth in medium containing a selection agent for the selectable marker, including an aminoglycosidic antibiotic, such as kanamycin, neomycin, or G418 (see e.g., U.S. Pat. No. 4,965,199).

One suitable selection gene for use in yeast is the trp1 gene present in the yeast plasmid YRp7 (Stinchcomb et al., Nature, 282: 39 (1979)). The trp1 gene provides a selection marker for a mutant strain of yeast lacking the ability to grow in tryptophan, for example, ATCC No. 44076 or PEP4-1 (see, e.g., Jones, Genetics, 85: 12 (1977)). The presence of the trp1 lesion in the yeast host cell genome then provides an effective environment for detecting transformation by growth in the absence of tryptophan. Similarly, Leu2-deficient yeast strains (ATCC 20,622 or 38,626) are complemented by known plasmids bearing the Leu2 gene.

In addition, vectors derived from the 1.6μ circular plasmid pKD1 can be used for transformation of Kluyveromyces yeasts. Alternatively, an expression system for large-scale production of recombinant calf chymosin was reported for K. lactis by Van den Berg, Bio/Technology, 8:135 (1990). Stable multi-copy expression vectors for secretion of mature recombinant human serum albumin by industrial strains of Kluyveromyces have also been disclosed (see, e.g., Fleer et al., Bio/Technology, 9: 968-975 (1991)).

Expression and cloning vectors usually contain a promoter that is recognized by the host organism and is operably linked to the anti-α2 integrin antibody nucleic acid. Promoters suitable for use with prokaryotic hosts include the arabinose promoter (e.g., araB), phoA promoter, β-lactamase and lactose promoter systems, alkaline phosphatase, a tryptophan (trp) promoter system, and hybrid promoters such as the tac promoter. However, other known bacterial promoters are suitable. Promoters for use in bacterial systems also will contain a Shine-Dalgamo (S.D.) sequence operably linked to the DNA encoding the anti-α2 integrin antibody.

Promoter sequences are known for eukaryotes. Most eukaryotic genes have an AT-rich region located approximately 25 to 30 bases upstream from the site where transcription is initiated. Another sequence found 70 to 80 bases upstream from the start of transcription of many genes is a CNCAAT (SEQ ID NO:115) region where N may be any nucleotide. At the 3′ end of most eukaryotic genes is an AATAAA (SEQ ID NO:116) sequence that may be the signal for addition of the poly A tail to the 3′ end of the coding sequence. Such sequences are suitably inserted into eukaryotic expression vectors.

Examples of suitable promoter sequences for use with yeast hosts include but are not limited to the promoters for 3-phosphoglycerate kinase or other glycolytic enzymes, such as enolase, glyceraldehyde-3-phosphate dehydrogenase, hexokinase, pyruvate decarboxylase, phosphofructokinase, glucose-6-phosphate isomerase, 3-phosphoglycerate mutase, pyruvate kinase, triosephosphate isomerase, phosphoglucose isomerase, and glucokinase. Other yeast promoters, which are inducible promoters having the additional advantage of transcription controlled by growth conditions, are the promoter regions for alcohol dehydrogenase 2, isocytochrome C, acid phosphatase, degradative enzymes associated with nitrogen metabolism, metallothionein, glyceraldehyde-3-phosphate dehydrogenase, and enzymes responsible for maltose and galactose utilization. Suitable vectors and promoters for use in yeast expression are further described in EP 73,657. Yeast enhancers also are advantageously used with yeast promoters.

Anti-α2 integrin antibody transcription from vectors in mammalian host cells is controlled, for example, by promoters obtained from the genomes of viruses such as polyoma virus, fowlpox virus, adenovirus (such as Adenovirus 2), bovine papilloma virus, avian sarcoma virus, cytomegalovirus; a retrovirus, hepatitis-B virus or Simian Virus 40 (SV40), from heterologous mammalian promoters, for example, the actin promoter or an immunoglobulin promoter, from heat-shock promoters, provided such promoters are compatible with the host cell systems. The early and late promoters of the SV40 virus are conveniently obtained as an SV40 restriction fragment that also contains the SV40 viral origin of replication. The immediate early promoter of the human cytomegalovirus is conveniently obtained as a HindIII E restriction fragment. A system for expressing DNA in mammalian hosts using the bovine papilloma virus as a vector is disclosed in U.S. Pat. No. 4,419,446, and a modification of this system is described in U.S. Pat. No. 4,601,978 (see, also Reyes et al., Nature 297: 598-601 (1982) on expression of human β-interferon cDNA in mouse cells under the control of a thymidine kinase promoter from herpes simplex virus). Alternatively, the rous sarcoma virus long terminal repeat can be used as the promoter.

Transcription of DNA encoding an anti-α2 integrin antibody by higher eukaryotes is often increased by inserting an enhancer sequence into the vector. Many enhancer sequences are now known from mammalian genes (globin, elastase, albumin, α-fetoprotein, and insulin). Often, however, an enhancer from a eukaryotic cell virus is used. Examples include the SV40 enhancer on the late side of the replication origin (bp 100-270), the cytomegalovirus early promoter enhancer, the polyoma enhancer on the late side of the replication origin, and adenovirus enhancers (see, also, e.g., Yaniv, Nature 297: 17-18 (1982) on enhancing elements for activation of eukaryotic promoters). The enhancer may be spliced into the vector at a position 5′ or 3′ to the anti-α2 integrin antibody-encoding sequence, but is preferably located at a site 5′ from the promoter. Other gene regulation systems well known in the art (e.g. inducible systems, such as tetracycline inducible systems and GeneSwitch™) can be used to control the transcription of DNA encoding an anti-α2 integrin.

Expression vectors used in eukaryotic host cells (yeast, fungi, insect, plant, animal, human, or nucleated cells from other multicellular organisms) will also contain sequences necessary for the termination of transcription and for stabilizing the mRNA. Such sequences are commonly available from the 5′ and, occasionally 3′, untranslated regions of eukaryotic or viral DNAs or cDNAs. These regions contain nucleotide segments transcribed as polyadenylated fragments in the untranslated portion of the mRNA encoding an anti-α2 integrin antibody. One useful transcription termination component is the bovine growth hormone polyadenylation region (see, e.g., WO94/11026 and the expression vector disclosed therein).

Suitable host cells for cloning or expressing the DNA in the vectors herein are the prokaryote, yeast, or higher eukaryote cells as described above. Suitable prokaryotes for this purpose include eubacteria, including gram-negative or gram-positive organisms, for example, Enterobacteriaceae such as Escherichia, e.g., E. coli, Enterobacter, Erwinia, Klebsiella, Proteus, Salmonella, e.g., Salmonella typhimurium, Serratia, e.g., Serratia marcescans, and Shigella, as well as Bacilli such as B. subtilis and B. licheniformis, Pseudomonas such as P. aeruginosa, and Streptomyces. Suitable E. coli cloning hosts include E. coli 294 (ATCC 31,446), E. coli B, E. coli X1776 (ATCC 31,537), and E. coli W3110 (ATCC 27,325).

In addition to prokaryotes, eukaryotic microbes such as filamentous fungi or yeast are suitable cloning or expression hosts for anti-alpha 2 integrin antibody-encoding vectors. Saccharomyces cerevisiae, or common baker's yeast, is the most commonly used among lower eukaryotic host microorganisms. However, a number of other genera, species, and strains are commonly available and useful, such as Schizosaccharomyces pombe; Kluyveromyces hosts including K. lactis, K. fragilis (ATCC 12,424), K. bulgaricus (ATCC 16,045), K. wickeramii (ATCC 24,178), K. waltii (ATCC 56,500), K. drosophilarum (ATCC 36,906), K. thermotolerans, or K. marxianus; yarrowia (EP 402,226); Pichia pastoris (EP 183,070); Candida; Trichoderma reesia (EP 244,234); Neurospora crassa; Schwanniomyces such as Schwanniomyces occidentalis; and filamentous fungi including Neurospora, Penicillium, Tolypocladium, or Aspergillus hosts such as A. nidulans or A. niger.

Suitable host cells for the expression of glycosylated anti-α2 integrin antibody are derived from multicellular organisms. Examples of invertebrate cells include plant and insect cells. Numerous baculoviral strains and variants and corresponding permissive insect host cells from hosts such as Spodoptera frugiperda (caterpillar), Aedes aegypti (mosquito), Aedes albopictus (mosquito), Drosophila melanogaster (fruitfly), and Bombyx mori have been identified. A variety of viral strains for transfection are publicly available, for example, the L-1 variant of Autographa californica NPV and the Bm-5 strain of Bombyx mori NPV, and such viruses may be used, particularly for transfection of Spodoptera frugiperda cells.

Plant cell cultures of cotton, corn, potato, soybean, petunia, tomato, and tobacco can also be utilized as hosts.

However, interest has been greatest in vertebrate cells, and propagation of vertebrate cells, including a variety of mammalian cells, has become routine procedure. Examples of useful mammalian host cells include: a monkey kidney CV1 line transformed by SV40 (e.g., COS-7, ATCC CRL 1651); a human embryonic kidney line 293 or 293 cells subcloned for growth in suspension culture (see e.g., Graham et al., J. Gen Virol. 36: 59 (1977)); baby hamster kidney cells (e.g., BHK, ATCC CCL 10); Chinese hamster ovary (CHO) cells, including CHO cells lacking DHFR (see, e.g., DHFR Urlaub et al., Proc. Natl. Acad. Sci. USA 77: 4216 (1980)); mouse sertoli cells ((e.g., TM4, Mather, Biol. Reprod. 23: 243-251 (1980)); monkey kidney cells (e.g., CV1 ATCC CCL 70); African green monkey kidney cells (e.g., VERO-76, ATCC CRL-1587); human cervical carcinoma cells (e.g., HELA, ATCC CCL 2); canine kidney cells (e.g., MDCK, ATCC CCL 34); buffalo rat liver cells (e.g., BRL 3A, ATCC CRL 1442); human lung cells (e.g., W138, ATCC CCL 75); human liver cells (e.g., Hep G2, HB 8065); mouse mammary tumor (e.g., MMT 060562, ATCC CCL51); TRI cells (see, e.g., Mather et al., Annals N.Y. Acad. Sci. 383: 44-68 (1982)); MRC 5 cells; FS4 cells; or a human hepatoma line (e.g., Hep G2).

Host cells are transformed with an above-described expression or cloning vectors for anti-α2 integrin antibody production and cultured in conventional nutrient media modified as appropriate for inducing promoters, selecting transformants and/or amplifying the genes encoding the desired sequences.

The host cells used to produce an anti-α2 integrin antibody may be cultured in a variety of media. Commercially available media such as Ham's F10 (Sigma), Minimal Essential Medium ((MEM), (Sigma), RPMI-1640 (Sigma), and Dulbecco's Modified Eagle's Medium ((DMEM), Sigma) are suitable for culturing the host cells. In addition, any of the media described in Ham et al., Meth. Enz. 58: 44 (1979), Barnes et al., Anal. Biochem. 102: 255 (1980), U.S. Pat. Nos. 4,767,704; 4,657,866; 4,927,762; 4,560,655; or 5,122,469; WO90103430; WO 87/00195; or U.S. Pat. Re. No. 30,985 may be used as culture media for the host cells. Any of these media may be supplemented as necessary with hormones and/or other growth factors (such as insulin, transferrin, or epidermal growth factor), salts (such as sodium chloride, calcium, magnesium, and phosphate), buffers (such as HEPES), nucleotides (such as adenosine and thymidine), antibiotics (such as GENTAMYCIN™ drug), trace elements (defined as inorganic compounds usually present at final concentrations in the micromolar range), and glucose or an equivalent energy source. Any other necessary supplements may also be included at appropriate concentrations that would be known to those skilled in the art. Culture conditions, such as temperature, pH, and the like, are selected by those skilled in the art, including those culture conditions previously used with the host cell selected for expression.

Anti-α2 integrin antibodies can be purified from cells, including microbial or mammalian cells using, for example, protein A chromatography, ion exchange chromatography, hydrophobic interaction chromatography, gel electrophoresis, dialysis, and/or affinity chromatography. The suitability of protein A as an affinity ligand depends on the species and isotype of any immunoglobulin Fc domain that is present in the antibody. Protein A can be used to purify antibodies that are based on human γ1, γ2, or γ4 heavy chains (see, e.g., Lindmark et al., J. Immunol. Meth. 62:1-13 (1983)). Protein G is useful for mouse isotypes and for human γ3 (see, e.g., Guss et al, EMBO J. 5:1516-1517 (1986)). The matrix to which the affinity ligand is attached is most often agarose, but other matrices are available. Mechanically stable matrices such as controlled pore glass or poly(styrenedivinyl)benzene allow for faster flow rates and shorter processing times than can be achieved with agarose. Where the antibody comprises a CH3 domain, the Bakerbond ABX™ (J.T. Baker, Phillipsburg, N.J.) is useful for purification. Protein purification can include one or more of the following techniques such as fractionation on an ion-exchange column, ethanol precipitation, Reverse Phase HPLC, chromatography on silica, chromatography on heparin SEPHAROSE™, chromatography on an anion or cation exchange resin (e.g., a polyaspartic acid column), chromatofocusing, SDS-PAGE, ammonium sulfate precipitation and/or hydrophobic interaction chromatography. For example, it may be useful following any purification step(s), to subject a mixture comprising the antibody of interest and contaminants to low pH hydrophobic interaction chromatography using an elution buffer at a pH between about 2.5-4.5, preferably performed at low salt concentrations (e.g., from about 0-0.25M salt).

Formulations of an anti-α2 integrin antibody, including those for therapeutic administration, are prepared for storage by mixing the antibody having the desired degree of purity with optional physiologically acceptable carriers, diluents, excipients or stabilizers (Remington's Pharmaceutical Sciences 16th edition, Osol, A. Ed. (1980)), in the form of lyophilized formulations or aqueous solutions. Acceptable carriers, diluents, excipients, or stabilizers are nontoxic to recipients at the dosages and concentrations employed, and include buffers such as phosphate, citrate, and other organic acids; antioxidants including ascorbic acid and methionine; preservatives (such as octadecyldimethylbenzyl ammonium chloride; hexamethonium chloride; benzalkonium chloride, benzethonium chloride; phenol, butyl or benzyl alcohol; alkyl parabens such as methyl or propyl paraben; catechol; resorcinol; cyclohexanol; 3-pentanol; and m-cresol); low molecular weight (less than about 10 residues) polypeptides; proteins, such as serum albumin, gelatin, or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone; amino acids such as glycine, glutamine, asparagine, histidine, arginine, or lysine; monosaccharides, disaccharides, or other carbohydrates including glucose, mannose, or dextrins; chelating agents such as EDTA; sugars such as sucrose, mannitol, trehalose or sorbitol; salt-forming counter-ions such as sodium; metal complexes (e.g., Zn-protein complexes); and/or non-ionic surfactants such as TWEEN™, PLURONICS™ or polyethylene glycol (PEG). For therapeutic uses the anti-α2 integrin antibody of the present invention may be formulated e.g. in phosphate buffered saline (PBS) containing 0,03% Tween-80™. The antibody formulation may also contain more than one active compound for the particular indication being treated, preferably those with complementary activities that do not adversely affect each other. It may be desirable to use anti-α2 integrin antibody in addition to one or more agents currently used to prevent or treat the disorder in question. In addition, it may be desirable to further provide an immunosuppressive agent. Such molecules are suitably present in combination in amounts that are effective for the purpose intended.

The active ingredients may also be entrapped in microcapsule prepared, for example, by coacervation techniques or by interfacial polymerization, for example, hydroxymethylcellulose or gelatin-microcapsule and poly-(methylmethacylate) microcapsule, respectively, in colloidal drug delivery systems (for example, liposomes, albumin microspheres, microemulsions, nano-particles or nanocapsules) or in macroemulsions. Such techniques are disclosed, for example, in Remington's Pharmaceutical Sciences 16th edition, Osol, A. Ed. (1980).

Formulations to be used for in vivo administration are preferably sterile. This is readily accomplished, for example, by filtration through sterile filtration membranes.

Sustained-release preparations may be prepared. Suitable examples of sustained-release preparations include semipermeable matrices of solid hydrophobic polymers containing the antibody, which matrices are in the form of shaped articles, e.g., films, or microcapsule. Examples of sustained-release matrices include polyesters, hydrogels (for example, poly(2-hydroxyethyl-methacrylate), or poly(vinylalcohol)), polylactides (U.S. Pat. No. 3,773,919), copolymers of L-glutamic acid and γ ethyl-L-glutamate, non-degradable ethylene-vinyl acetate, degradable lactic acid-glycolic acid copolymers such as the Lupron Depot™ (injectable microspheres composed of lactic acid-glycolic acid copolymer and leuprolide acetate), and poly-D-(−)-3-hydroxybutyric acid. While polymers such as ethylene-vinyl acetate and lactic acid-glycolic acid enable release of molecules for over 100 days, certain hydrogels release proteins for shorter time periods. When encapsulated antibodies remain in the body for a long time, they may denature or aggregate as a result of exposure to moisture at 37° C., resulting in a loss of biological activity and possible changes in immunogenicity. Rational strategies can be devised for stabilization depending on the mechanism involved. For example, if the aggregation mechanism is discovered to be intermolecular S—S bond formation through thio-disulfide interchange, stabilization may be achieved by modifying sulfhydryl residues, lyophilizing from acidic solutions, controlling moisture content, using appropriate additives, and developing specific polymer matrix compositions.

The anti-α2 integrin antibody is administered by any suitable means, including parenteral, subcutaneous, intraperitoneal, intrapulmonary, or intranasal. If desired for local immunosuppressive treatment, intralesional administration of the antibody (including perfusing or otherwise contacting the graft with the antibody before transplantation) is done. Parenteral administration includes intramuscular, intravenous, intraarterial, intraperitoneal, or subcutaneous administration. In addition, the anti-α2 integrin antibody is suitably administered by pulse infusion, for example, with declining doses of the antibody. Preferably the dosing is given by injections, most preferably intravenous or subcutaneous injections. This may depend in part on whether the administration is brief or chronic. More preferably the anti-α2 integrin antibodies or the compositions as described herein are administered in the methods of the present invention by intravenous infusion, intravenous bolus, subcutaneous administration, subcutaneous infusion or subcutaneous bolus, whereas intravenous infusion or intravenous bolus is most preferred. The term “intravenous infusion” refers to introduction of a drug into the vein of an animal or human patient over a period of time greater than approximately 5 minutes, preferably between approximately 30 to 90 minutes, although, according to the invention, intravenous infusion is alternatively administered for 10 hours or less. The term “intravenous bolus” or “intravenous push” refers to drug administration into a vein of an animal or human such that the body receives the drug in approximately 15 minutes or less, preferably 5 minutes or less. The term “subcutaneous administration” refers to introduction of a drug under the skin of an animal or human patient, preferable within a pocket between the skin and underlying tissue, by relatively slow, sustained delivery from a drug receptacle. The pocket may be created by pinching or drawing the skin up and away from underlying tissue. The term “subcutaneous infusion” refers to introduction of a drug under the skin of an animal or human patient, preferably within a pocket between the skin and underlying tissue, by relatively slow, sustained delivery from a drug receptacle for a period of time including, but not limited to, 30 minutes or less, or 90 minutes or less. The term “subcutaneous bolus” refers to drug administration beneath the skin of an animal or human patient, where bolus drug delivery is preferably less than approximately 15 minutes, more preferably less than 5 minutes, and most preferably less than 60 seconds. Administration is preferably within a pocket between the skin and underlying tissue, where the pocket is created, for example,—by pinching or drawing the skin up and away from underlying tissue. Optionally, the infusion may be made by subcutaneous implantation of a drug delivery pump implanted under the skin of the animal or human patient, wherein the pump delivers a predetermined amount of drug for a predetermined period of time, such as 30 minutes, 90 minutes, or a time period spanning the length of the treatment regimen. Intermittent or periodic dosing is a dosing that is continuous for a certain period of time and is at regular intervals that are preferably separated more than by one day.

“Therapeutically effective amount” or “effective amount” which are used synonymously herein, refer to an amount of the anti-α2 integrin antibodies described herein effective to ameliorate or prevent the symptoms, or prolong the survival of the subject being treated. Determination of a therapeutically effective amount is well within the capabilities of those skilled in the art, especially in light of the detailed disclosure provided herein. The term “therapeutically effective amount” of the anti-α2 integrin antibodies described herein specifically refers to the amount needed to delay or inhibit tumor growth.

For the prevention or treatment of cancer, the appropriate dosage of antibody will depend on the type of disease to be treated, as defined above, the severity and course of the disease, whether the anti-α2 integrin antibody is administered for preventive or therapeutic purposes, previous therapy, the patient's clinical history and response to the antibody, and the discretion of the attending physician. The antibody is suitably administered to the patient at one time or over a series of treatments.

The anti-α2 integrin antibodies can be thus administered to a subject, preferably to human, in the method of the present invention, at a therapeutically effective amount ranging from about 0.1. to about 100 mg/kg. Preferably, a therapeutically effective amount ranging from about 1 to about 20 mg/kg, more preferably a therapeutically effective amount ranging from about 3 to about 10 mg/kg is administered to a subject, preferably to human. A therapeutically effective amount of the humanized antibody or binding fragment thereof can be administered to the subject in one or more therapeutically effective doses.

Depending on the type and severity of the disease from about 0.1 mg/kg to about 100 mg/kg of antibody is an initial candidate dosage for administration to the subject, whether, for example, by one or more separate administrations, or by continuous infusion. A typical daily dosage to e.g. human might range from 0.1 mg/k to 20 mg/kg or more, depending on the factors mentioned above. For repeated administrations over several days or longer, depending on the condition, the treatment is sustained until a desired suppression of disease symptoms occurs. However, other dosage regimens may be useful. The progress of this therapy is readily monitored by those skilled in the art. According to toxicokinetics studies as described in example 6 the anti-α2 integrin antibodies of the present invention have an estimated half life T½ of between 199 and 316 hours. Thus a once every two weeks dosis regimen seems preferable.

Unexpectedly the anti-alpha 2 (α2) integrin antibodies used in the present invention inhibit tumor growth to a degree comparable to anti-VEGF antibodies. Specifically at a dose of 50 mg/kg of anti-alpha 2 (α2) integrin antibody administered biweekly for 22 days in a mouse xenograft study the size of the tumor was around 60% of the isotype control on day 27. Thus the invention provides a method of treating cancer selected from the group consisting of squamous cell cancer, lung cancer including small-cell lung cancer, non-small cell lung cancer, adenocarcinoma of the lung, and squamous carcinoma of the lung, cancer of the peritoneum, hepatocellular cancer, gastric or stomach cancer including gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, colorectal cancer, endometrial or uterine carcinoma, salivary gland carcinoma, kidney or renal cancer, liver cancer, prostate cancer, vulval cancer, thyroid cancer, hepatic carcinoma and various types of head and neck cancer, as well as B-cell lymphoma including low grade/follicular non-Hodgkin's lymphoma (NHL); small lymphocytic (SL) NHL; intermediate grade/follicular NHL; intermediate grade diffuse NHL; high grade immunoblastic NHL; high grade lymphoblastic NHL; high grade small non-cleaved cell NHL; bulky disease NHL; mantle cell lymphoma; AIDS-related lymphoma; and Waldenstrom's Macroglobulinemia; chronic lymphocytic leukemia (CLL); acute lymphoblastic leukemia (ALL); Hairy cell leukemia; chronic myeloblastic leukemia; and post-transplant lymphoproliferative disorder (PTLD), as well as abnormal vascular proliferation associated with phakomatoses, edema such as that associated with brain tumors, Meigs' syndrome, melanoma, mesothelioma, multiple myeloma, fibrosarcoma, osteosarcoma, and epidermoid carcinoma, by administering to a subject a therapeutically effective amount of a humanized anti-α2 integrin antibody, whereas the size of the tumor treated with the humanized anti-α2 integrin antibody is equal to or less than 90%, preferably equal to or less than 80%, more preferably equal to or less than 70%, most preferably equal to or less than 60%, in particular equal to or less than 50%, more particular equal to or less than 40%, most particular equal to or less than 30% of the size of the tumor treated with the control antibody, whereas the size of the tumor is usually measured as tumor volume or tumor weight.

An anti-α2 integrin antibody composition will be formulated, dosed, and administered in a fashion consistent with good medical practice. Factors for consideration in this context include the particular disorder being treated, the particular mammal being treated, the clinical condition of the individual patient, the cause of the disorder, the site of delivery of the agent, the method of administration, the scheduling of administration, results from pharmacological and toxicity studies and other factors known to medical practitioners. A therapeutically effective amount of the antibody to be administered is determined by consideration of such, and is the minimum amount necessary to prevent, ameliorate, or treat an α2β1 integrin-associated disorder. Such amount is preferably below the amount that is toxic to the host or renders the host significantly more susceptible to infections.

The anti-α2 integrin antibody need not be, but may be optionally formulated, co-administered or used as an adjunct therapy with one or more agents currently used to prevent or treat the disorder in question. For example, the antibody may be given in conjunction with radiotherapy and or one or several cancer medications. These cancer medications may comprise another antibody, chemo-therapeutic agent, cytotoxic agent, anti-angiogenic agent, immunosuppressive agent, prodrug, cytokine, cytokine antagonist, cytotoxic radiotherapy, corticosteroid, anti-emetic cancer vaccine, analgesic, anti-vascular agent, or growth-inhibitory agent. More specific agents include, for example, irinotecan (CAMPTOSAR®), cetuximab (ERBITUX®), fulvestrant (FASLODEX®), vinorelbine (NAVELBINE®), EFG-recep-tor antagonists such as erlotinib (TARCEVA®) VEGF antagonists such as bevacizumab (AVASTIN®), vincristine (ONCOVIN®), inhibitors of mTor (a serine/threonine protein kinase) such as rapamycin and CCI-779, and anti-HER1, HER2, ErbB, and/or EGFR antagonists such as trastuzumab (HERCEPTIN®), pertuzumab (OMNI-TARG™), or lapatinib, and other cytotoxic agents including chemotherapeutic agents. Alternatively, or in addition, α2β1 integrin antagonists may be administered to the mammal suffering from an α2β1 integrin-associated disorder. The effective amount of such other agents depends on the amount of anti-α2 integrin antibody present in the formulation, the type of disorder or treatment, and other factors discussed above. These are generally used in the same dosages and with administration routes as used hereinbefore or about from 1 to 99% of the heretofore employed dosages.

An article of manufacture containing materials, including an anti-α2 integrin antibody, useful for the treatment of the cancer as described above is provided. The article of manufacture comprises a container and a label. Suitable containers include, for example, bottles, vials, syringes, and test tubes. The containers may be formed from a variety of materials such as glass or plastic. The container holds a composition which is effective for treating the condition and may have a sterile access port (for example the container may be an intravenous solution bag or a vial having a stopper pierceable by a hypodermic injection needle). The active agent in the composition is an anti-alpha 2 integrin antibody. The label on, or associated with, the container indicates that the composition is used for treating the cancer as described above. The article of manufacture may further comprise a second container comprising a pharmaceutically-acceptable buffer, such as phosphate-buffered saline, Ringer's solution or dextrose solution. It may further include other materials desirable from a commercial and user standpoint, including other buffers, diluents, filters, needles, syringes, and package inserts with instructions for use.

The following examples are offered by way of illustration and not by way of limitation. The disclosures of all citations in the specification are expressly incorporated herein by reference.

EXAMPLES Example 1 In Vitro Evaluation of Anti-α₂ Integrin Antibody Potencies in Inhibiting Interaction Between Human α₂ Integrin Expressed on Human Carcinoma Cell Lines and Human Collagen

An in vitro binding assay between human cell line and human collagen has been established to assess the potency of different anti-α₂ integrin antibodies to inhibit the interaction between human VLA-2 (α₂β₁) integrin expressed on human carcinoma cell lines and human collagen type I. In this assay, fluorescently labelled human pancreatic cancer cell lines that naturally expresses VLA-2 were distributed in 96 well plates which have been previously coated with human collagen type I. A fluorescently labelled human pancreatic cancer cell line that doesn't express VLA-2 was used as a negative control. Fluorescently-labelled cells were then incubated in the collagen coated 96 well plates in presence of different concentrations of the anti-α₂ integrin (GBR500 or TMC2206) or isotype-matched control antibody (GBR600) for one hour. Plates were gently washed and the remaining fluorescence was measured in each well of the plate. The strength of the fluorescence signal measured in each individual well is proportional to the number of cells that have adhered to the collagen.

Material and Methods

TABLE 1 Antibodies Clone number or antibody Catalogue name Supplier number Description TMC-2206 Glenmark/ MAB1998 Mouse anti-human α₂ integrin Millipore GBR500 Glenmark NA Humanized anti-human α₂ integrin GBR600 Glenmark NA Humanized IgG₄ control antibody

The humanized anti-human α₂ integrin GBR500 as referred herein comprises a heavy chain comprising SEQ ID NO:187 and a light chain comprising SEQ ID NO:188.

TABLE 2 Cell lines VLA-2 Name Source Supplier Cat# expression SK-BR-3 Breast Carcinoma ATCC HTB-30 Low AsPC-1 Pancreatic ATCC CRL-1682 High Carcinoma HPAF-II Pancreatic ATCC CRL-1997 High Carcinoma MIA PaCa-2 Pancreatic ATCC CRL-1420 Negative Carcinoma

Flow Cytometry

After incubation with Versene (Gibco, cat#15040), AsPC-1 cells, HPAF-II cells and MIA PaCa-2 cells were collected and resuspended in PBS-2.5% FBS at a concentration of 1×10⁶ cells/mL. One hundred μl of the cell suspension was incubated with 10 μg/mL of GBR500-FITC or hIgG4-FITC as a control for 20 minutes on ice. Cells were washed twice with PBS-2.5% FBS and analyzed by flow cytometry. Trypsinised SK-BR-3 cell line were treated in the same way as described for the pancreatic cell line. Expression level of VLA-2 molecule was expressed as the Mean Fluorescence Intensity (MFI).

Collagen Binding Assay

Ninety six well ELISA plates (black cliniplate, Thermo Firsher scientific, cat no 9502867) were coated with 100 μl of human collagen type I (SIGMA, cat no C7774) at 50 μg/mL in Acetic Acid 0.02N or in PBS. Collagen was either diluted in acetic acid and incubated for 1 hour at 37° C. or diluted in PBS and incubated overnight at 4° C. Plates were blocked with 150 μl of PBS supplemented with 0.1% BSA or 1% BSA (Sigma, cat no A3059). Cells were first labelled with CFSE (Invitrogen cat no C34554) into serum free DMEM medium (PAA, cat no E15-005). Three μl of a 15 mM CFSE solution was added to 5 ml cells at a concentration between 1×10⁶ cells/ml to 0.6×10⁶ cells/ml. Cells were incubated with CFSE for 10 minutes at 37° C. and CFSE excess was removed by centrifugation of the cells at 900 rpm for 3 min. CFSE-labelled cells were resuspended at a concentration between 0.6×10⁶ to 1×10⁶ cells/ml in DMEM supplemented with 0.1% BSA. Fifty μl of antibody dilutions in DMEM-0.1% BSA were distributed to the collagen coated plate and fifty μl of CFSE labelled cells were immediately distributed to the plate. GBR600 antibody was used as an isotype control antibody for GBR500. Plates were incubated at room temperature for 1 hour and cells that were not bound to the collagen were removed by dumping the supernatant. Plates were washed four times with PBS buffer either manually or using BioTek washer. Wells in the plates were filled with PBS and fluorescence with excitation at 498 nm and emission at 525 nm was measured using Synerg HT2 fluorometer. Data were analyzed using PRISM software. Activity of the anti-VLA-2 antibody was expressed as EC₅₀ which is defined as the concentration of antibody that provokes a response halfway between the baseline and the maximum response.

Results:

TABLE 3 FACS staining MFI Cell line hIgG4 GBR500 AsPC-1  6.8  69.8 HPAF-Il 14.9 166.5 MIA PaCa-2  4.9  5.0 SK-BR-3  3.4  6.0

Collagen Binding Assay

Collagen binding assay using the three pancreatic cancer cell lines and the breast cancer cell line were performed twice. Table 4 summarizes the EC-50 values obtained in the 2 experiments performed is depicted below.

TABLE 4 EC-50 values Experiment I Experiment II EC₅₀ EC₅₀ EC₅₀ EC₅₀ Cell line GBR500 TMC2206 GBR500 TMC2206 AsPC-1 0.047 μg/mL  0.074 μg/mL 0.036 μg/mL 0.087 μg/mL HPAF-II 0.224 μg/mL 0.3257 μg/mL 0.103 μg/mL 0.253 μg/mL MIA Paca-2 No cell binding No cell binding SK-BR-3 0.039 μg/mL 0.032 μg/mL

GBR500 and TMC-2206 antibodies inhibited the binding of the VLA-2 positive pancreatic and breast cancer cells to the human collagen. The MIA PaCa-2 cell line which doesn't express VLA-2 doesn't bind to the collagen. This result demonstrates that VLA-2 expression is a prerequisite for cell adherence to collagen type I.

Conclusion

1) α2 integrin expression on the carcinoma cancer cell lines AsPC-1, HPAF-II and SKBR3 cells can be detected using fluorescently-labelled GBR500 antibody. The pancreatic cancer cell line express a higher level of the α2 integrin compare to the breast cancer cell line. 2) The VLA-2 positive cell lines AsPC-1, HPAF-II and SK-BR-3 cell lines adhered to the collagen whereas the VLA-2 negative cell line MiaPaCA doesn't. 3) Antibody EC-50 values for the inhibition of collagen binding for the different cell lines tested are shown in Table 5:

TABLE 5 EC-50 values Cell lines GBR500 EC₅₀ TMC-2206 EC₅₀ AsPC-1 0.041 ± 0.008 (n = 2) 0.080 ± 0.009 (n = 2) HPAF-II 0.163 ± 0.086 (n = 2) 0.290 ± 0.051 (n = 2) MiaPaCa No cell binding No cell binding SK-BR-3 0.036 ± 0.005 (n = 2) Not done

The EC₅₀ value obtained with the HPAF-II cell line was about 4 times (3.9 times for GBR500 and 3.6 for TMC-2206) higher compared to the EC₅₀ value measured for AsPC-1 cell line. This difference cannot be attributed to VLA-2 expression level, since both pancreatic cell lines expressed similar VLA-2 levels (see FACS staining data). Moreover, the SK-BR-3 cell line expressing a low level of VLA-2, displayed an EC₅₀ value comparable to AsPC-1 (high VLA-2 expression). However, the collagen coating conditions were different between the pancreatic cell lines and the breast cancer cell line (collagen diluted acid acetic at 37° C. for one hour versus collagen diluted in PBS at 4° C. overnight), therefore EC50 value comparisons between these cell lines should be interpreted with caution.

4) This study identifies α₂β₁ integrin mediated adhesion to type I collagen as a potential therapeutic target. Moreover, the anti-VLA-2 antibody GBR500 and TMC2206 displayed a good capacity to inhibit the binding of VLA-2 expressing cell lines to collagen. GBR500 antibody is therefore a potential therapeutic candidate in the treatment of pancreatic and breast cancers.

Example 2 Effect of GBR500 Against the Human Pancreatic Carcinoma Tumour Xenograft AsPC-1 in BALB/c Nude (nu/nu) Athymic Mice

Female BALB/c nude (nu/nu) athymic mice, of at least 6-8 weeks age were used in the xenograft study. Animals obtained from Australian Research Council (ARC) were assigned into treatment groups on day −2 of the study and treatment was being started as per the regime described in Table 6. On day 1 human AsPC-1 pancreatic carcinoma tumour cells (ATCC® Number: CRL-1682) were harvested from sub-confluent cultures grown in vitro and the number of viable cells determined. Cells were re-suspended in 1×PBS at a concentration of 5×10⁷ cells/ml and animals were injected subcutaneously in the rear right flank with approximately 5×10⁶ cells in a volume of 0.1 ml. Animals were examined regularly for the appearance of tumours and dosed biweekly for 22 days starting from day −2 (Total 7 injections on days −2,2,6,9, 13, 16, 20). Antibodies were administered in a volume of 10 ml/kg. At day 20 treatments were stopped and animals were monitored up to day 27.

TABLE 6 Treatment Groups and Study Design Route of Number adminis- of Group Treatment Dose level Treatment Days tration animals 1 Isotype control 50 mg/kg biweekly* for 22 IP 14 days 2 Avastin ® 40 mg/kg biweekly for 22 IP 14 days 3 GBR500  5 mg/kg biweekly for 22 IP 14 days 4 GBR500 50 mg/kg biweekly for 22 IP 14 days 5 Cetuximab 40 mg/kg biweekly for 22 IP 14 days *Biweekly for 22 days starting from day −2 (Total 7 injections on days −2, 2, 6, 9, 13, 16, 20)

Tumour measurements were obtained twice weekly using digital callipers for the duration of the study. Tumour dimensions were recorded (length and width), and tumour volumes calculated using the formula W²×L×0.536, where W is the widest tumour dimension and

L is the longest. The results of the study are shown in FIG. 1. The tumor volumes refer to the mean per group of 14 animals. At a dose of 50 mg/kg GBR500, the size of the tumor was around 60% of the isotype control on day 27.

Example 3 Effect of GBR500 Against the HT29 Human Colon Carcinoma Xenograft in nu/nu Athymic Mice

Nu/Nu male mice, from Harlan, Italy, were used. The animals were maintained in cages using steam autoclaved (sterile) bedding, diet and water were offered ad libitum. Animals were identified by a uniquely numbered ear-tag which appears on the data sheets. Body weight at the day of tumor implantation was: 24-31 g.

Number of Groups—Treatment Schedule:

Number of groups was 5. Number of animals/group was 10. Treatment was being started as per the regime described in Table 7.

TABLE 7 Treatment Groups and Study Design Dose Group Compound mg/kg Route/Schedule 1 IgG4 Isotype 50  IP* Day 6, 9, 13, 16, 20, 23, 27** 2 Ha1/29  5 IP Day 6, 9, 13, 16, 20, 23, 27** 3 GBR500 50 IP Day 6, 9, 13, 16, 20, 23, 27** 4 Ha1/29 + 50 + 5 IP Day 6, 9, 13, 16, 20, 23, 27** GBR500 5 Avastin ® 40 IP Day 6, 9, 13, 16, 20, 23, 27** *IP: intraperitoneally **Treatment starts at day 6 after tumor implants

Substances:

Test compounds were stored at 4° C. temperature and protected from light until use. Test compounds were dissolved in 0,03% Tween-80™ in Phosphate buffered saline and were diluted immediately before use in order to reach the right concentration (IgG4 Isotype, Ha1/29 and GBR500 in PBS; Avastin® in saline solution). Treatments were administered intraperitoneally (IP) in a volume of 10 ml/kg

Tumor:

HT29 tumor fragment from mice previously inoculated with HT29 cells (ATCC HTB-38™) were implanted subcutaneously into the left flank of athymic nude mice. Animals were examined regularly for the appearance of tumors. When measurable tumors have been established in the majority of mice, animals were assigned into treatment groups, with a target of 10 mice per group (5 mice per cage). When treatment starts the mean tumor volume was 120 mm³.

Evaluation of Antitumor Activity in the Xenograft Models and Toxicity:

At least twice a week the tumor growth and the net body weight were evaluated. Tumor growth was assessed by caliper. Dimensions of the tumors were measured regularly by calliper during the experiments, and tumor masses were calculated as follows:

${{Tumor}\mspace{14mu} {weight}\mspace{14mu} ({mg})} = {\frac{{{length}\mspace{14mu} ({mm})} - {{width}^{2}\mspace{14mu} ({mm})}}{2} \cdot {d\left( {{mg}\text{/}{mm}^{3}} \right)}}$

assuming density d=1 mg/mm³ for tumor tissue

Toxicity was evaluated on the basis of the body weight reduction. Mice were sacrificed when the tumors reach a volume that hampers them.

Results and Conclusions:

Ha 1/29 (5 mg/kg) and GBR500 (50 mg/kg) administered as single agents twice a week, gave a tumor weight inhibition at day 28 of 12% and 16%, respectively. Ha1/29 in combination with GBR500 showed a reduction of tumor weight of 19% (Table 8).

TABLE 8 Dosage scheme and tumor weight inhibition Dose Group Compound mg/kg % Tumor Weight Inhibition 6 9 13 16 20 23 28 31 35 1 IgG4 Isotype 50 — — — — — — — — — 2 Ha1/29  5 1 14 28 33 23 17 12 3 −4 3 GBR500 50 2 4 11 18 12 15 16 13  0 4 Ha1/29 + 50 + 5 2 17 24 33 23 25 19 7 −1 GBR500 5 Avastin ® 40 1 20 28 43 44 50 50 40 24

The maximal antitumor activity of antibodies treated groups was observed at day 16 with a tumor weight inhibition of 33, 18, 33% (Ha1/29, GBR500 and the combination group respectively). Avastin®, administered at 40 mg/kg, showed a tumor growth inhibition of 50% at day 28. In FIG. 2 the comparison of the average tumor growth observed in the different treatment groups is shown. Treatments were well tolerated and no dead mice in treated groups were found during the experiment. No signs of distress were observed during and after treatments and no significant body weight loss was observed.

Example 4 Detection of Expression Levels of CD49b (Integrin Subunit α2) in Human Cell Lines Cell Lines and Culture Conditions

A panel of cell lysates was screened for expression of CD49b. This panel consisted of lysates from four non-transformed human cell lines (BJ, 1407, primary fibroblasts, WRL-68) and 96 human cancer cell lines from different tissues/organs (including colorectal, skin, breast, prostate, pancreas, lung, cervix, kidney, ovary, CNS, bone, liver, thyroid, and blood). The cell lines used are shown in Table 9 A and 9B.

TABLE 9 A Cell Lines Tissue tumor origin Lane Cell Line Source Type Growth medium 1 fibrosarcoma 1 HT-1080 ECACC ADHESION E-MEM + 10% FCS + 2 mM L-Glutamine + 1% NEAA 2 adenocarcinoma colon 2 CACO-2 Ist. Zooprofilattico BS ADHESION E-MEM + 10% FCS + 2 mM L-Glutamine + 1% NEAA 3 CL-11 DSMZ ADHESION 80% mixture of Ham's F12

4 COLO-205 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 5 COLO-206F DSMZ ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 6 COLO-320 DSMZ ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 7 COLO-678 DSMZ ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 8 COLO-741 ICLC ADHESION RPMI 1640 + 10% FCS + 2 Mm Glut. 9 DLD-1 IEO (ATCC) ADHESION RPMI 1640 + 10% FCS + 2 Mm Glut.

10 HCC2998 NCl ADHESION RPMI 1640 + 10% FCS + 2 Mm Glut. 11 HCT-116 ECACC ADHESION McCoy's + 2 mM L-Glutamine + 10% FCS 12 HCT15 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 13 HT-29 ECACC ADHESION McCog's + 2 mM L-Glutamine + 10% FCS 14 KM12 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 15 LoVo ECACC ADHESION HAM's F12 + 10% FCS + 2 mM Glut. 16 LS-174T ATCC ADHESION E-MEM + 10% FCS + 2 mM L-Glutamine

17 LS-180 ICLC ADHESION MEM (EBSS) + 10% FCS + 2 Mm Glutamine

18 SW1417 ICLC ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 19 SW403 DSMZ ADHESION DMEM + 2 mM glutamine + 10% 20 SW48 ATCC ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 21 SW480 IEO (ATCC) ADHESION Leibovitz's L-

 + 10% FCS + 2 mM Glutamine or RPMI

22 SW620 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 23 T84 ATCC ADHESION Ham's F12 + DMEM

 10% FCS 3 non tumoral 24 BJ ADHESION

 + 10% FCS + 2 mM Glut. 25 1407 PHA ADHESION EMEM (EBSS) + 2 mM Glutamine + 1% Non Essential Amino Acids(NEAA) + 10% Faecal Bovine Serum (FBS) 26 NHDF PROMOCELL ADHESION Fibroblast basal medium + bullet kit

27 WRL-68 ECACC ADHESION E-MEM + 10% FCS + 2 mM L-Glutamine + 1% NEAA 4 melanoma 28 A375 ECACC ADHESION DMEM + 2 mM Glutamine + 10% FCS 29 Mewo ATCC ADHESION E-MEM + 10% FCS + 2 mM L-Glutamine + 1% NEAA 30 SK-MEL-28 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 31 SK-MEL-5 ATCC ADHESION RPMI 1640 + 10% FCs + 2 mM Glut. 32 UACC-257 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 5 adenocarcinoma mammary 33 BT-20 ATCC ADHESION E-MEM + 10% FCS + 2 mM L-Glutamine 34 MCF7 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 35 MDA-MB-231 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 36 MDA-MB-435S NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 37 MDA-MB-468 ITM ADHESION RPMI or Leibovitz's L-15 + 10% FCS + mM Glutamine 38 SK-BR-3 ATCC ADHESION McCoy's 2 mM L-Glutamine + 10% FCS 39 T47D ATCC ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 6 carcinoma prostate 40 DU-145 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 41 LnCap ATCC ADHESION RPMI 1640 + 10% FCS + 2 mM Glut +

42 PC-3 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 7 adenocarcinoma pancreas 43 BxPC-3 ECACC ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 44 CAPAN-1 DSMZ ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 45 MIA-PaCa-2 ECACC ADHESION DMEM + 2 mM Glutamine +

 FCS 46 PANC-1 ATCC ADHESION DMEM

 glutamine

 10% FCS 8 non-small cell lung cancer 47 A549 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 48 CAL-12T IFOM ADHESION DMEM + 2 mM Glutamine + 10% FCS 49 HOP-62 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 50 NCl-H1437 ATCC ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 51 NCl-H1770 ATCC SUSPENSION RPMI 1640 + 10% FCS + 2 mM Glut. 52 SK-LU-1 ICLC ADHESION MEM (EBSS) + 10% FCS + 2 mM glutamine +1% AAEE +

 Sodium pyruvate

indicates data missing or illegible when filed

TABLE 9 B Cell Lines Tissue tumor origin Lane Cell Line Source Type Growth medium  9 adenocarcinoma cervix 53 C-33-A IEO ADHESION RPMS 1640 + 10% FCS + 2 mM Glut. 54 HeLa ECACC ADHESION E-MEM + 10% FCS + 2 Mm L-Glutamine +

 NEAA 10 adenocarcinoma kidney 55 A498 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 56 ACHN NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 57 SN12C NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 58 TK10 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 59 U031 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 11 adenocarcinoma ovary 60 A2780 ECACC ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 61 IGROV-1 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 62 OVCAR-3 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 63 OVCAR-8 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 12 glioblastoma 64 SNB19 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 65 T98G ATCC ADHESION EMEM + 2 mM glut + 10% FCS + 1%(1.0 mM) sodium pyruvate 66 U251 NCl ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 67 U-87-MG ATCC ADHESION EMEM + 10% FCS + 2 mM L-Glutamine + 1% NEAA 13 osteosarcoma 68 U-2-OS ATCC ADHESION McCoy's + 2 mM L-Glutamine + 10% FCS 14 non-small cell lung cancer 69 NCl-H1299 ATCC ADHESION RPMI 1640 + 10% FCS + 10 mM HEPES + 1 mM Na Pyruvate + 2 mM Glut. 70 NCl-H1975 ATCC ADHESION RPMI 1640 + 20% FCS 15 small cell lung cancer 71 NCl-H146 ATCC SUSPENSION RPMI 1640 + 10% FCS + 2 mM Glut. + 10 mM HEPES, and 1.0 Mm Sodium pyruvate 72 NCl-H1963 ATCC SUSPENSION RPMI 1640 + 10% FCS + 2 mM Glut. 73 NCl-H209 ATCC SUSPENSION RPMI 1640 medium, 90% fetal bovine serum 10% 74 NCl-H526 ATCC SUSPENSION RPMI 1640 + 10% FCS + 2 mM Glut. + 10 mM HEPES and 1.0 mM sodium pyruvate 75 NCl-H69 ATCC SUSPENSION RPMI 1640 medium with 2 m

 HEPES, and 1.0 mM sodium pyruvate + 10% FCSML-glutamate 76 NCl-H82 ATCC SUSPENSION RPMI 1640 + 10% FCS + 2 mM Glut. + 10 mM HEPES and 1.0 mM sodium pyruvate 77 NCl-N592 NMS SUSPENSION RPMI + 10% FCS + 1% HEPES + 1% Sodio Pyruvato 16 adenocarcinoma liver 78 HepG2 ECACC ADHESION E-MEM + 10% FCS + 2 mM L-Glutamine + 1% NEAA 17 papillary thyroid carcinoma 79 WRO Istituto Tumori ADHESION OMEM + Na piruvato +

18 carcinoma epidermoid 80 A431 ATCC ADHESION RPMI 1640 + 10% FCS 2 mM Glut. 19 mesothelioma 81 MSTO-211H Ospedale S.Mateo Pavia ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. + 10 mM HEPES, and 1.0 mM sodium pyruvate 82 REN Ospedale S.Matteo Pavia ADHESION RPMI 1640 + 10% FCS + 2 mM Glut. 20 leukemia 83 HL-60 ECACC SUSPENSION RPMI 1640 + 10% FCS + 2 mM Glut. leukemia 84 K-562 ECACC SUSPENSION RPMI 1640 + 10% FCS + 2 mM Glut. leukemia T lymphoblastoid 85 CEM/VM1 W. Beck-St Jude Hospital SUSPENSION E-MEM + 10% FCS + 2 mM L-Glutamine + 100

 VM26 leukemia T lymphoblastoid 86 KARPAS-299 DSMZ SUSPENSION RPMI 1640 + 10% FCS + 2 mM glutamine thrombocythemia leukemic 87 SET-2 DSMZ SUSPENSION RPMI 1640 + 20% FBS multiple myeloma 88 KMS-11 Istituto Tumori SUSPENSION RPMI 1640 + 10% FCS + 2 mM glutamine multiple myeloma 89 RPMI-8226 ECACC SUSPENSION RPMI 1640 + 10% FCS + 2 mM Glut. multiple myeloma 90 RPMI-8226 DSMZ SUSPENSION RPMI 1640 + 10% FCS + 2 mM Glut. Leukemia B cell 91 697 DSMZ SUSPENSION RPMI 1640 + 10% FCS + 2 mM Glut. Leukemia B cell 92 MEC-1 DSMZ SUSPENSION

% Iscove's MDM + 10% FBS Leukemia B cell 93 NALM-6 DSMZ SUSPENSION RPMI 1640 + 10% FCS + 2 mM glutamine leukemia B cell 94 RS4-11 ATCC SUSPENSION RPMI 1640 medium with 2 mM L-glutamine adjusted to contain 1.5 g/L sodium bicarbonate, 4.5 g/L glucose, 10 mM HEPES, and 1.0 mM sodium pyruvate + 10% fetal bovine Lymphoma B cell 95 GRANTA-519 DSMZ SUSPENSION DMEM + 2 mM glutamine + 10% Lymphoma B cell 96 SU-DHL-10 DSMZ SUSPENSION 80-90% RPMI 1640 + 10-20% FBS Lymphoma B cell 97 SU-DHL-4 DSMZ SUSPENSION 80-90% RPMI 1640 + 10-20% FBS Lymphoma B cell 98 SU-DHL-6 DSMZ SUSPENSION 80-90% RPMI 1640 + 10-20% FBS Lymphoma B cell 99 SUP-B15 DSMZ SUSPENSION 80% McCoy's 5A + 20% FBS Lymphoma 100  SUP-M2 DSMZ SUSPENSION RPMI 1640 + 10% FCS + 2 mM Glut.

indicates data missing or illegible when filed

Lysate Preparation for Western Blot

The lysates are prepared from sub-confluent cultures of cell lines maintained in appropriate growth medium in the presence of 10% Foetal Bovine Serum (see table 8 for details). Adherent cell lines were seeded in 150 mm plates (cells harvested at approx. 60-70% confluency); suspension cell lines were grown in T-175 flasks (cells harvested at approx. 200,000 cells/ml).

Protocol for Adherent Cell Lines:

1) Wash plate with cold PBS (without Ca2+ and Mg2+). Remove PBS. 2) Allow excess PBS to drain to one side and remove. 3) Add 1 ml cold lysis buffer and put plate on ice. Scrape the cells. 4) Collect the lysate and wash the plate with another 200 μl lysis buffer and add to the lysate, agitate in cold room for 15 min. 6) Spin for 15 min in microfuge (15000 rpm at 4° C.). 7) Recover supernatant and freeze in aliquots in liquid Nitrogen. 8) Determine protein concentration in an aliquot of each lysate using a BSA reference curve. 9) Bring samples to 1 mg/ml with complete Lysis Buffer, 4×LDS Sample Buffer, 20× Reducing Agent (1M DTT) and boil 10 min.

Protocol for Suspension Cell Lines:

1) Spin cell suspension for 15 min (2000 rpm at 4° C.) and remove medium. 2) Wash with cold PBS (without Ca2+ and Mg2+), spin for 15 min (2000 rpm at 4° C.) and remove PBS. 3) Add 1 ml cold lysis buffer and pipette the cell lysate in ice. 4 Keep cell/lysate agitating in cold room for 15 min.

6) Spin for 15 min (15000 rpm at 4° C.).

7) Recover supernatant and freeze in aliquots in liquid Nitrogen. 8) Determine protein concentration in all lysates in parallel using the same BSA reference curve. 9) Bring samples to 1 mg/ml with Complete Lysis Buffer, 4×LDS Sample Buffer, 20× Reducing Agent (1M DTT) and boil 10 min.

Complete Lysis Buffer Composition:

 50 mM Hepes pH 7.5 150 mM NaCl   1% Tritonx-100   1% Deoxycholate 0.1% SDS  10 mM EDTA

Add DTT (final 1 mM) and protease/phosphatase inhibitor cocktails (Sigma P-2850, P-5726, P-8340) as required just before use. DTT Reducing Agent (Biorad, cat. #161-0610): 50 mM final concentration.

LDS Sample Buffer Composition (Invitrogen, Cat. #02 98 22 201):

  106 mM Tris HCl pH 8.5   150 mM Tris base 1% TritonX-100  2% LDS 10% glycerol  0.51 mM EDTA  0.22 mM Serva Blue G250 0.175 mM Phenol Red

Western Blot

Protein extracts (10 μg proteins/sample) were resolved by SDS-PAGE using 4-12% Bis-Tris Midi gels (Invitrogen) according to manufacturer's instructions. Membranes were stained with Ponceau Red after transfer. Anti-CD49b and anti-GAPDH antibodies were used diluted 1:1000 and 1:2000, respectively, in blocking buffer containing 5% non-fat dry milk. HRP-conjugated secondary antibodies were used 1:5000 in blocking buffer containing 5% non-fat dry milk.

Antibodies Used in the Study

-   -   Mouse monoclonal IgG2a anti-CD49b (Integrin α₂ chain) antibody         (Becton Dickinson, cat. #611016);     -   Rabbit polyclonal IgG anti-GAPDH (Glyceraldehyde 3-phosphate         dehydrogenase) antibody (Santa Cruz Biotechnology, cat. #         sc-25778);     -   HRP-conjugated anti-mouse and anti-rabbit antibodies (Pierce);     -   Biotin-GBR500 (lot AT-220208A) recombinant humanized monoclonal         antibody;     -   Biotin-IgG4 (lot AT-090108A) recombinant humanized monoclonal         antibody (Glenmark Pharmaceuticals S.A.);     -   Fluorolink™Cy™2 goat anti-mouse IgG (GE Healthcare, cat. #         PA42002);     -   Streptavidin-FITC (BD Pharmingen, ca. #554060).

Sample Preparation for Immunofluorescence

Cells were cultured in Lab-Tek chamber slides (Nunc) for 48 hours (70,000 cells/chamber), and afterwards fixed with formaldehyde 3.7% (v/v) for 20 minutes. Cells were washed twice with PBS, then saturated for 30 minutes with a blocking solution containing 1% (w/v) bovine serum albumin (BSA) and 0.3% (v/v) Triton X-100 (Sigma-Aldrich) in PBS. Primary antibodies were added at the recommended dilution in blocking solution. After 1 hour incubation at 37° C., the solution was removed and cells were washed twice with PBS.

Secondary antibodies, or alternatively Streptavidin-FITC, were added in blocking solution at the recommended dilution together with 1 mg/ml DRAQ5™ (Alexis, cat. # BOS-889-001-R200). Slides were incubated for 1 hour at 37° C., then the solution was removed and cells washed twice with PBS. PBS was removed and slides were mounted with coverslips using a Mowiol solution (Mowiol 4.88, Calbiochem cat. #475904).

Laser-Scanning Confocal Microscopy

Immunofluorescence pictures were obtained using an Axioplan microscope (Zeiss) coupled with a Radiance 2000 laser scanning system (Bio-Rad, 40× objective, oil immersion). Acquisition was performed using Kalman filter (10 iterations); laser power was equal for the same fluorescence channel in different samples.

Results and Conclusions Western Blot Analysis of CD49b Expression in Human Cell Lines

Ponceau Red staining of membranes confirmed homogeneous transfer of cellular proteins to membrane.

Western Blot analyses for CD49b and GAPDH expression are shown in FIG. 3. Overall, CD49b is ubiquitously expressed in adherent cell lines, but not in suspension ones (leukemias—block 15 and SCLCs—block 20). There are some exceptions of a few adherent cell lines with undetectable CD49b levels (for example, MIA PaCa-2 and U031), and conversely, of cell lines which grow in suspension expressing high CD49b levels (CEM/VM1 and RS4-11). All cell lines show consistent GAPDH expression, used as a loading/WB control.

The highest levels of CD49b were found in the following cell lines:

-   -   HT-1080 (fibrosarcoma);     -   BxPC-3 (adenocarcinoma pancreas);     -   CAL-12T (non-small cell lung cancer);     -   NCI-H1299 (non-small-cell lung cancer);     -   TK10 (adenocarcinoma kidney);     -   SNB19 and U251 (glioblastomas);     -   A431 (epidermoid carcinoma).

Regarding colorectal carcinomas, the majority of the 22 tested lines exhibited homogenous, moderately high relative expression of CD49b. In only 3/22 tested lines, expression levels were relatively low, but still readily detectable by Western Blot.

CD49b Detection in Selected Cell Lines by Confocal Microscopy Using GBR500 Antibody

Confocal microscopy was used to test whether Western Blot data obtained using Becton-Dickinson anti-CD49b correlated with cell surface expression using GBR500. In the samples studied, cell lines with high expression of the antigen as judged by Western blot were also found to exhibit specific immunoreactivity at the plasma membrane using GBR500. Human tumor cell lines which express CD49b at the plasma membrane and which therefore could be suitable for in vivo studies include HT-29 colorectal carcinoma and BX-PC3 pancreatic carcinoma lines, though many further candidates have been identified in this study.

Five selected cell lines (HT-1080, BxPC-3, MIAPaCa2, HT-29 and SW480) were immunostained with Biotin-GBR500 and biotin-hIgG4 (unrelated isotype) and analysed by laser-scanning confocal microscopy. These tumor cell lines were selected on the basis of results obtained by Western Blotting using BD anti-CD49b antibody:

BxPC-3: pancreatic carcinoma with high level of CD49b MIAPaCa2: pancreatic carcinoma with undetectable CD49b HT-29: colorectal carcinoma with moderately high level of CD49b SW480: colorectal carcinoma with relatively low, but detectable level of CD49b

The fibrosarcoma cell line HT1080, known to express high levels of CD49b, was used as positive control: confocal microscopy confirms strong membrane staining concentrated at lamellipodia-like areas of the plasma membrane (FIG. 4).

As shown in the images reported in FIG. 5 (BxPC-3) and FIG. 6 (MIA PaCa2) there does appear to be correlation between Western Blot data obtained with the BD antibody and immunocytochemistry results obtained with GBR500: BxPC-3 are strongly positive, while MIAPaCa2 are negative for staining with GBR500. In particular, confocal microscopy revealed strong biotin-GRB500, but not biotin-hIgG4, immunostaining of cell membrane within areas of cell-to-cell contact for BxPC-3. This is a distinct staining pattern compared to HT-1080 cells, where GBR500 staining is confined to possibly lamellipodia-like regions of the plasma membrane.

The colon adenocarcinoma cell line HT-29 showed intense biotin-GRB500 immunostaining (FIG. 7), with a distribution similar to that observed in BX-PC-3 cells.

In SW480 cells, another line with low CD49b expression as judged by Western Blot, biotin-GBR500 staining was nearly indistinguishable from biotin-IgG4 staining (FIG. 8), confirming a low CD49b expression level detected by Western Blot.

In conclusion, CD49b expression was detected in the majority of colon carcinoma cell lines, as well as several other solid tumor types, where it is commonly detected. CD49b expression is relatively rare in Small Cell Lung Carcinoma, and leukemias/lymphomas. Highest expressing cell lines as judged by Western Blot are HT-1080 (fibrosarcoma), BxPC-3 (pancreatic adenocarcinoma), CAL-12T (non-small cell lung cancer), NCI-H1299 (non-small-cell lung cancer), TK10 (renal adenocarcinoma), SNB19 and U251 (glioblastomas).

Example 5 Effect of GBR500 Against the A549 Non Small Cell Lung Cancer Xenograft in nu/nu Athymic Mice

Nu/Nu male mice, from Harlan, Italy, were used. The animals were maintained in cages using steam autoclaved (sterile) bedding, diet and water were offered ad libitum. Animals were identified by a uniquely numbered ear-tag which appears on the data sheets. Body weight at the day of tumor implantation was: 24-31 g.

Number of Groups—Treatment Schedule:

Number of groups was 4. Number of animals/group was 10. Treatment was being started at day 6 after tumor implantation until day 27 as per the regime described in Table 10.

TABLE 10 Treatment Groups and Study Design Dose Group Compound mg/kg Route/Schedule 1 IgG4 Isotype 50  IP* Day 6, 9, 13, 16, 20, 23, 27** 2 Ha1/29 + 5 + 5  IP Day 6, 9, 13, 16, 20, 23, 27** GBR500 3 Ha1/29 + 5 + 50 IP Day 6, 9, 13, 16, 20, 23, 27** GBR500 4 Avastin ® 40 IP Day 6, 9, 13, 16, 20, 23, 27** *IP: intraperitoneally **Treatment starts at day 6 after tumor implants

Substances:

Test compounds were stored at 4° C. temperature and protected from light until use. Test compounds were dissolved in 0,03% Tween-80™ in Phosphate buffered saline and were diluted immediately before use in order to reach the right concentration (IgG4 Isotype, Ha1/29 and GBR500 in PBS; Avastin® in saline solution). Treatments were administered intraperitoneally (IP) in a volume of 10 ml/kg

Tumor:

The A549 epitelial lung carcinoma cell line (ATCCO Number: CCL-185) was used as a representative for non small lung cell cancer. Tumor fragments from a A549 xenograft were implanted subcutaneously into the left flank of athymic nude mice. Animals were examined regularly for the appearance of tumors. When measurable tumors have been established in the majority of mice, animals were assigned into treatment groups, with a target of 10 mice per group (5 mice per cage). When treatment starts the mean tumor volume was 120 mm³.

Evaluation of Antitumor Activity in the Xenograft Models and Toxicity:

At least twice a week the tumor growth and the net body weight were evaluated. Tumor growth was assessed by caliper. Dimensions of the tumors were measured regularly by calliper during the experiments, and tumor masses were calculated as follows:

${{Tumor}\mspace{14mu} {weight}\mspace{14mu} ({mg})} = {\frac{{{length}\mspace{14mu} ({mm})} - {{width}^{2}\mspace{14mu} ({mm})}}{2} \cdot {d\left( {{mg}\text{/}{mm}^{3}} \right)}}$

assuming density d=1 mg/mm³ for tumor tissue

Toxicity was evaluated on the basis of the body weight reduction. Mice were sacrificed when the tumors reach a volume that hampers them.

Results and Conclusions:

As can be seen from Table 11 the maximal antitumor activity of antibodies treated groups was observed at day 17 with a tumor weight inhibition of 18% and 11% (Ha1/29+GBR500 combination groups respectively). Avastin®, administered at 40 mg/kg, showed a tumor growth inhibition of 20% at day 28. In FIG. 9 the comparison of the average tumor growth observed in the different treatment groups is shown. Treatments were well tolerated and no dead mice in treated groups were found during the experiment. No signs of distress were observed during and after treatments and no significant body weight loss was observed.

TABLE 11 Treatment Groups and Study Design Dose Group Compound mg/kg % Tumor Weight Inhibition  7 10 14 17 21 24 28    1 IgG4 Isotype 50 — — — — — — — 2 Ha1/29 + 5 + 5  −3  3 15 18 14  3  0% GBR500 3 Ha1/29 + 5 + 50 −4  5 14 11 11 11  9    GBR500 4 Avastin ® 40 −4  3 10 12 17 18 20   

Example 6 GBR500 Toxicokinetics in Cynomolgus Monkeys

As part of a 6-week toxicity study with toxicokinetic endpoints Cynomolgus monkeys were dosed via slow intravenous infusion of GBR 500 over approximately 60 minutes. The animals were dosed once per week for six weeks. (days 1, 8, 15, 22, 29, and 36). Dose Group Assignment and Dose Levels are summarized in Table 12 below:

TABLE 12 Dose Group Assignment and Dose Levels Group Number of Males/Females Dose Level (mg/kg) 1 5/5 0 (control) 2 3/3  10 3 3/3  30 4 3/3 100

Blood samples of 1 ml were taken from animals on Day 1 (predose, 15 minutes, 4, 8, 24, 48 and 120 hours post infusion, Day 8 (predose, 15 minutes post infusion), Day 15 (predose, 15 minutes post infusion), Day 22 (predose, 15 minutes post infusion), Day 29 (predose, 15 minutes post infusion), Day 36 (predose, 15 minutes, 4, 8, 24, 48 and 120 hours post infusion), and Days 50, 57, 64, 71, 78, 84, 91, and 98. GBR 500 concentration was determined with a validated ELISA assay.

The toxicokinetic (TK) profile of each animal was characterized by non-compartmental analysis of the GBR 500 serum concentration using validated computer software (WinNonlin, version 3.2, Pharsight Corp., Mountain View, Calif., USA). A model was selected based on the vascular route of administration and the serum matrix. The concentration at time zero on Day 1 was assumed to be 0 for the purpose of parameter estimation. Serum concentration values obtained at the predose time-point were used to estimate the concentration at time zero on Day 36.

For the Group 4 recovery animals, the half life T½ was estimated between 199 and 316 hours, the volume of distribution Vz was estimated between 10.1-23.6 mL/kg, and the clearance CL between 0.03-0.60 mL/hr/kg. Vz and CL estimates indicated that GBR500 was not distributed beyond the plasma and was very slowly cleared from it. FIGS. 10A and 10 B show the concentration curves of the 100 mg dose group for male and female monkeys.

Example 7 In Vitro Evaluation of Anti-α₂ Integrin Antibody Potencies in Inhibiting Interaction Between Human α₂ Integrin Expressed on Human Fibrosarcoma Cell Line and Human Collagen Material and Methods

Flow cytometry and collagen binding inhibition assays were performed as described in Example 1. A fibrosarcoma cell line HT-1080 was used in the experiments (Table 13). HT-1080 was trypsinized to prepare cells for flow cytometry as described for SK-BR-3

TABLE 13 Cell lines VLA-2 Name Source Supplier Cat# expression HT-1080 Fibrosarcoma ATCC CCL-121 High

Results

TABLE 14 FACS staining MFI Cell line hIgG4 GBR500 HT-1080 4.9 165.1

VLA-2 expression by HT-1080 was high.

Collagen Binding Assay

TABLE 15 EC-50 values Cell lines GBR500 EC₅₀ TMC-2206 EC₅₀ HT-1080 0.076 ± 0.045 (n = 3) 0.097 ± 0.038 (n = 3)

GBR 500 and TMC-2206 inhibited binding of HT-1080 cells to human collagen I.

Conclusion

α2 integrin expression on the fibrosarcoma cell line HT-1080 was detected using fluorescently-labelled GBR500 antibody. The level of expression VLA-2 is high.

The VLA-2 positive cell line HT-1080 adhered to human collagen type I. This binding was inhibited by VLA-2 antibodies GBR 500 and TMC-2206.

Example 8 Effect of GBR500 Against the HT-1080 Fibrosarcoma Xenograft in nu/nu Athymic Mice

Nu/Nu male mice, from Harlan, Italy, were used. The animals were maintained in cages using steam autoclaved (sterile) bedding, diet and water were offered ad libitum. Animals were identified by a uniquely numbered ear-tag which appears on the data sheets. Body weight at the day of tumor implantation was: 24-31 g.

Number of Groups—Treatment Schedule:

Number of groups was 4. Number of animals/group was 10. Treatment was being started as per the regime described in Table 16.

TABLE 16 Treatment Groups and Study Design Dose Group Compound mg/kg Route/Schedule 1 IgG4 Isotype 50  IP* Day 6, 9, 13, 16, 20, 23, 27** 2 Ha1/29 + 5 + 5  IP Day 6, 9, 13, 16, 20, 23, 27** GBR500 3 Ha1/29 + 5 + 50 IP Day 6, 9, 13, 16, 20, 23, 27** GBR500 4 Avastin ® 40 IP Day 6, 9, 13, 16, 20, 23, 27** *IP: intraperitoneally **Treatment starts at day 6 after tumor implants

Substances:

Test compounds were stored at 4° C. temperature and protected from light until use. Test compounds were dissolved in 0,03% Tween-80™ in Phosphate buffered saline and were diluted immediately before use in order to reach the right concentration (IgG4 Isotype, Ha1/29 and GBR500 in PBS; Avastin® in saline solution). Treatments were administered intraperitoneally (IP) in a volume of 10 ml/kg.

Tumor:

The HT-1080 fibrosarcoma cell line (ATCC® Number: CCL-121) was used. Tumor fragments from a HT-1080 xenograft were implanted subcutaneously into the left flank of athymic nude mice. Animals were examined regularly for the appearance of tumors.

When measurable tumors have been established in the majority of mice, animals were assigned into treatment groups, with a target of 10 mice per group (5 mice per cage). When treatment starts the mean tumor volume was about 300 mm³.

Evaluation of Antitumor Activity in the Xenograft Models and Toxicity:

At least twice a week the tumor growth and the net body weight were evaluated. Tumor growth was assessed by caliper. Dimensions of the tumors were measured regularly by calliper during the experiments, and tumor masses were calculated as follows:

${{Tumor}\mspace{14mu} {weight}\mspace{14mu} ({mg})} = {\frac{{{length}\mspace{14mu} ({mm})} - {{width}^{2}\mspace{14mu} ({mm})}}{2} \cdot {d\left( {{mg}\text{/}{mm}^{3}} \right)}}$

assuming density d=1 mg/mm³ for tumor tissue

Toxicity was evaluated on the basis of the body weight reduction. Mice were sacrificed when the tumors reach a volume that hampers them.

Results and Conclusions:

At day 11, after two doses of the antibody, Avastin led to a reduction of tumor weight of 31.6% relative to control. The Ha 1/29 5 mg/GBR500 5 mg combination led to a tumor weight reduction of 3.5% and the Ha 1/29 5 mg/GBR500 50 mg combination led to a tumor weight reduction of 27.7% (Table 17).

TABLE 17 Treatment Groups and Study Design Dose % Tumor Weight Inhibition Group Compound mg/kg Day 11 Day 11 1 IgG4 Isotype 50  0   2 Ha1/29 + 5 + 5   3.5 GBR500 3 Ha1/29 + 5 + 50 27.7 GBR500 4 Avastin ® 40 31.6

Treatments were well tolerated and no dead mice in treated groups were found during the experiment. No signs of distress were observed during and after treatments and no significant body weight loss was observed. 

1. A formulation for administration to a subject in need thereof, comprising: a) an anti-α2 integrin antibody; b) about 0.03% Tween-80; and c) phosphate buffered saline.
 2. The formulation of claim 1, wherein the anti-α2 integrin antibody comprises a heavy chain variable region and a light chain variable region, the heavy chain variable region comprising complementary determining regions (CDRs) comprising the amino acid sequences of SEQ ID NOS: 1, 2, and 3, and the light chain variable region comprising CDRs comprising the amino acid sequences of SEQ ID NOS: 112, 5, and
 6. 3. The formulation of claim 2, wherein the anti-α2 integrin antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO: 187 and a light chain comprising the amino acid sequence of SEQ ID NO:
 188. 4. The formulation of claim 1, wherein the anti-α2 integrin antibody is present at a concentration from about 0.5 mg/ml to about 5 mg/ml.
 5. The formulation of claim 1, wherein the formulation is a liquid formulation.
 6. The formulation of claim 1, wherein the formulation is a lyophilized formulation.
 7. The formulation of claim 1 for use in the treatment of a cancer selected from the group consisting of: squamous cell cancer, lung cancer including small-cell lung cancer, non-small cell lung cancer, adenocarcinoma of the lung, and squamous carcinoma of the lung, cancer of the peritoneum, hepatocellular cancer, gastric or stomach cancer including gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, colorectal cancer, endometrial or uterine carcinoma, salivary gland carcinoma, kidney or renal cancer, liver cancer, prostate cancer, vulval cancer, thyroid cancer, hepatic carcinoma and various types of head and neck cancer, as well as B-cell lymphoma including low grade/follicular non-Hodgkin's lymphoma (NHL); small lymphocytic (SL) NHL; intermediate grade/follicular NHL; intermediate grade diffuse NHL; high grade immunoblastic NHL; high grade lymphoblastic NHL; high grade small non-cleaved cell NHL; bulky disease NHL; mantle cell lymphoma; AIDS-related lymphoma; and Waldenstrom's Macroglobulinemia; chronic lymphocytic leukemia (CLL); acute lymphoblastic leukemia (ALL); Hairy cell leukemia; chronic myeloblastic leukemia; and post-transplant lymphoproliferative disorder (PTLD), as well as abnormal vascular proliferation associated with phakomatoses, edema such as that associated with brain tumors, Meigs' syndrome, melanoma, mesothelioma, multiple myeloma, fibrosarcoma, osteosarcoma, and epidermoid carcinoma.
 8. A kit comprising a container comprising the formulation of claim 1 and instructions for the administration and use of the formulation.
 9. The formulation of claim 1, wherein the formulation is administered to a subject to deliver from about 0.1 to about 100 mg/kg of the antibody.
 10. The formulation of claim 9, wherein the formulation is administered to a subject to deliver about 1 to about 20 mg/kg of the antibody.
 11. The formulation of claim 10, wherein the formulation is administered to a subject to deliver about 3 to about 10 mg/kg of the antibody. 